Write/Read delimited messages

18 files changed, 947 insertions, 12 deletions

diff --git a/src/AddressBook/AddressBookProtos.cs b/src/AddressBook/AddressBookProtos.cs
index 1e72d91a..0f5d743d 100644
--- a/src/AddressBook/AddressBookProtos.cs
+++ b/src/AddressBook/AddressBookProtos.cs
@@ -174,6 +174,12 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
         public static PhoneNumber ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static PhoneNumber ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static PhoneNumber ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static PhoneNumber ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -217,6 +223,9 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
           }
           
           public override PhoneNumber BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             PhoneNumber returnMe = result;
             result = null;
             return returnMe;
@@ -446,6 +455,12 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
     public static Person ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static Person ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static Person ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static Person ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -489,6 +504,9 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
       }
       
       public override Person BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.phone_.MakeReadOnly();
         Person returnMe = result;
         result = null;
@@ -753,6 +771,12 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
     public static AddressBook ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static AddressBook ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static AddressBook ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static AddressBook ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -796,6 +820,9 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
       }
       
       public override AddressBook BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.person_.MakeReadOnly();
         AddressBook returnMe = result;
         result = null;
diff --git a/src/ProtoGen/MessageGenerator.cs b/src/ProtoGen/MessageGenerator.cs
index 9857764d..4b983003 100644
--- a/src/ProtoGen/MessageGenerator.cs
+++ b/src/ProtoGen/MessageGenerator.cs
@@ -218,6 +218,12 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine("public static {0} ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {{", ClassName);
       writer.WriteLine("  return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();");
       writer.WriteLine("}");
+      writer.WriteLine("public static {0} ParseDelimitedFrom(global::System.IO.Stream input) {{", ClassName);
+      writer.WriteLine("  return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();");
+      writer.WriteLine("}");
+      writer.WriteLine("public static {0} ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {{", ClassName);
+      writer.WriteLine("  return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();");
+      writer.WriteLine("}");
       writer.WriteLine("public static {0} ParseFrom(pb::CodedInputStream input) {{", ClassName);
       writer.WriteLine("  return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();");
       writer.WriteLine("}");
@@ -325,6 +331,9 @@ namespace Google.ProtocolBuffers.ProtoGen {
     
       writer.WriteLine("public override {0} BuildPartial() {{", ClassName);
       writer.Indent();
+      writer.WriteLine("if (result == null) {");
+      writer.WriteLine("  throw new global::System.InvalidOperationException(\"build() has already been called on this Builder\");");
+      writer.WriteLine("}");
       foreach (FieldDescriptor field in Descriptor.Fields) {
         SourceGenerators.CreateFieldGenerator(field).GenerateBuildingCode(writer);
       }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
index 8462b6a7..b198d4f3 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
@@ -370,6 +370,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageWithCustomOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageWithCustomOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageWithCustomOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageWithCustomOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -413,6 +419,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageWithCustomOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageWithCustomOptions returnMe = result;
         result = null;
         return returnMe;
@@ -480,6 +489,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static CustomOptionFooRequest ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CustomOptionFooRequest ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CustomOptionFooRequest ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CustomOptionFooRequest ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -523,6 +538,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override CustomOptionFooRequest BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CustomOptionFooRequest returnMe = result;
         result = null;
         return returnMe;
@@ -571,6 +589,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static CustomOptionFooResponse ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CustomOptionFooResponse ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CustomOptionFooResponse ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CustomOptionFooResponse ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -614,6 +638,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override CustomOptionFooResponse BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CustomOptionFooResponse returnMe = result;
         result = null;
         return returnMe;
@@ -672,6 +699,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static DummyMessageContainingEnum ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static DummyMessageContainingEnum ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static DummyMessageContainingEnum ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static DummyMessageContainingEnum ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -715,6 +748,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override DummyMessageContainingEnum BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         DummyMessageContainingEnum returnMe = result;
         result = null;
         return returnMe;
@@ -763,6 +799,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static DummyMessageInvalidAsOptionType ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static DummyMessageInvalidAsOptionType ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static DummyMessageInvalidAsOptionType ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static DummyMessageInvalidAsOptionType ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -806,6 +848,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override DummyMessageInvalidAsOptionType BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         DummyMessageInvalidAsOptionType returnMe = result;
         result = null;
         return returnMe;
@@ -854,6 +899,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static CustomOptionMinIntegerValues ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CustomOptionMinIntegerValues ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CustomOptionMinIntegerValues ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CustomOptionMinIntegerValues ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -897,6 +948,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override CustomOptionMinIntegerValues BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CustomOptionMinIntegerValues returnMe = result;
         result = null;
         return returnMe;
@@ -945,6 +999,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static CustomOptionMaxIntegerValues ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CustomOptionMaxIntegerValues ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CustomOptionMaxIntegerValues ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CustomOptionMaxIntegerValues ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -988,6 +1048,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override CustomOptionMaxIntegerValues BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CustomOptionMaxIntegerValues returnMe = result;
         result = null;
         return returnMe;
@@ -1036,6 +1099,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static CustomOptionOtherValues ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CustomOptionOtherValues ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CustomOptionOtherValues ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CustomOptionOtherValues ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1079,6 +1148,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override CustomOptionOtherValues BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CustomOptionOtherValues returnMe = result;
         result = null;
         return returnMe;
@@ -1127,6 +1199,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static SettingRealsFromPositiveInts ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static SettingRealsFromPositiveInts ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static SettingRealsFromPositiveInts ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static SettingRealsFromPositiveInts ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1170,6 +1248,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override SettingRealsFromPositiveInts BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         SettingRealsFromPositiveInts returnMe = result;
         result = null;
         return returnMe;
@@ -1218,6 +1299,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static SettingRealsFromNegativeInts ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static SettingRealsFromNegativeInts ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static SettingRealsFromNegativeInts ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static SettingRealsFromNegativeInts ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1261,6 +1348,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override SettingRealsFromNegativeInts BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         SettingRealsFromNegativeInts returnMe = result;
         result = null;
         return returnMe;
@@ -1319,6 +1409,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static ComplexOptionType1 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ComplexOptionType1 ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ComplexOptionType1 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ComplexOptionType1 ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1362,6 +1458,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override ComplexOptionType1 BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         ComplexOptionType1 returnMe = result;
         result = null;
         return returnMe;
@@ -1465,6 +1564,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static ComplexOptionType4 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static ComplexOptionType4 ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static ComplexOptionType4 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static ComplexOptionType4 ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -1508,6 +1613,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override ComplexOptionType4 BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             ComplexOptionType4 returnMe = result;
             result = null;
             return returnMe;
@@ -1585,6 +1693,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static ComplexOptionType2 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ComplexOptionType2 ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ComplexOptionType2 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ComplexOptionType2 ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1628,6 +1742,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override ComplexOptionType2 BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         ComplexOptionType2 returnMe = result;
         result = null;
         return returnMe;
@@ -1800,6 +1917,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static ComplexOptionType5 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static ComplexOptionType5 ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static ComplexOptionType5 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static ComplexOptionType5 ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -1843,6 +1966,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override ComplexOptionType5 BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             ComplexOptionType5 returnMe = result;
             result = null;
             return returnMe;
@@ -1910,6 +2036,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static ComplexOptionType3 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ComplexOptionType3 ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ComplexOptionType3 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ComplexOptionType3 ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1953,6 +2085,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override ComplexOptionType3 BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         ComplexOptionType3 returnMe = result;
         result = null;
         return returnMe;
@@ -2065,6 +2200,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static ComplexOpt6 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ComplexOpt6 ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ComplexOpt6 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ComplexOpt6 ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -2108,6 +2249,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override ComplexOpt6 BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         ComplexOpt6 returnMe = result;
         result = null;
         return returnMe;
@@ -2174,6 +2318,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static VariousComplexOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static VariousComplexOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static VariousComplexOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static VariousComplexOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -2217,6 +2367,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override VariousComplexOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         VariousComplexOptions returnMe = result;
         result = null;
         return returnMe;
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs
index 8e610b7e..72c52ea2 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs
@@ -141,6 +141,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestEmbedOptimizedForSize ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestEmbedOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestEmbedOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestEmbedOptimizedForSize ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -184,6 +190,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestEmbedOptimizedForSize BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.repeatedMessage_.MakeReadOnly();
         TestEmbedOptimizedForSize returnMe = result;
         result = null;
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs
index 63372c63..45168b6c 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs
@@ -123,6 +123,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static ImportMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ImportMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ImportMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ImportMessage ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -166,6 +172,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override ImportMessage BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         ImportMessage returnMe = result;
         result = null;
         return returnMe;
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs
index 550bd429..c21a552b 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs
@@ -136,6 +136,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageSet ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageSet ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageSet ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageSet ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -179,6 +185,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageSet BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageSet returnMe = result;
         result = null;
         return returnMe;
@@ -314,6 +323,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageSetContainer ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageSetContainer ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageSetContainer ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageSetContainer ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -357,6 +372,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageSetContainer BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageSetContainer returnMe = result;
         result = null;
         return returnMe;
@@ -542,6 +560,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageSetExtension1 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageSetExtension1 ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageSetExtension1 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageSetExtension1 ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -585,6 +609,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageSetExtension1 BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageSetExtension1 returnMe = result;
         result = null;
         return returnMe;
@@ -747,6 +774,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageSetExtension2 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageSetExtension2 ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageSetExtension2 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageSetExtension2 ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -790,6 +823,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageSetExtension2 BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageSetExtension2 returnMe = result;
         result = null;
         return returnMe;
@@ -992,6 +1028,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static Item ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static Item ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static Item ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static Item ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -1035,6 +1077,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override Item BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             Item returnMe = result;
             result = null;
             return returnMe;
@@ -1203,6 +1248,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static RawMessageSet ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static RawMessageSet ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static RawMessageSet ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static RawMessageSet ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1246,6 +1297,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override RawMessageSet BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.item_.MakeReadOnly();
         RawMessageSet returnMe = result;
         result = null;
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestOptimizeForProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestOptimizeForProtoFile.cs
index f640a0b4..0e4c1afd 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestOptimizeForProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestOptimizeForProtoFile.cs
@@ -119,6 +119,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestOptimizedForSize ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestOptimizedForSize ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -162,6 +168,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestOptimizedForSize BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestOptimizedForSize returnMe = result;
         result = null;
         return returnMe;
@@ -274,6 +283,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestRequiredOptimizedForSize ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestRequiredOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestRequiredOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestRequiredOptimizedForSize ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -317,6 +332,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestRequiredOptimizedForSize BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestRequiredOptimizedForSize returnMe = result;
         result = null;
         return returnMe;
@@ -393,6 +411,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestOptionalOptimizedForSize ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestOptionalOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestOptionalOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestOptionalOptimizedForSize ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -436,6 +460,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestOptionalOptimizedForSize BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestOptionalOptimizedForSize returnMe = result;
         result = null;
         return returnMe;
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestProtoFile.cs
index 301bd60a..8a94d2da 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestProtoFile.cs
@@ -916,6 +916,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static NestedMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static NestedMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static NestedMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static NestedMessage ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -959,6 +965,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override NestedMessage BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             NestedMessage returnMe = result;
             result = null;
             return returnMe;
@@ -1118,6 +1127,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static OptionalGroup ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static OptionalGroup ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static OptionalGroup ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static OptionalGroup ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -1161,6 +1176,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override OptionalGroup BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             OptionalGroup returnMe = result;
             result = null;
             return returnMe;
@@ -1320,6 +1338,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static RepeatedGroup ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static RepeatedGroup ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static RepeatedGroup ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static RepeatedGroup ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -1363,6 +1387,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override RepeatedGroup BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             RepeatedGroup returnMe = result;
             result = null;
             return returnMe;
@@ -2755,6 +2782,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestAllTypes ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestAllTypes ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestAllTypes ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestAllTypes ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -2798,6 +2831,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestAllTypes BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.repeatedInt32_.MakeReadOnly();
         result.repeatedInt64_.MakeReadOnly();
         result.repeatedUint32_.MakeReadOnly();
@@ -5084,6 +5120,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static ForeignMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ForeignMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ForeignMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ForeignMessage ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -5127,6 +5169,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override ForeignMessage BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         ForeignMessage returnMe = result;
         result = null;
         return returnMe;
@@ -5274,6 +5319,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestAllExtensions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestAllExtensions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestAllExtensions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestAllExtensions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -5317,6 +5368,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestAllExtensions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestAllExtensions returnMe = result;
         result = null;
         return returnMe;
@@ -5452,6 +5506,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static OptionalGroup_extension ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static OptionalGroup_extension ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static OptionalGroup_extension ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static OptionalGroup_extension ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -5495,6 +5555,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override OptionalGroup_extension BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         OptionalGroup_extension returnMe = result;
         result = null;
         return returnMe;
@@ -5654,6 +5717,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static RepeatedGroup_extension ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static RepeatedGroup_extension ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static RepeatedGroup_extension ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static RepeatedGroup_extension ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -5697,6 +5766,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override RepeatedGroup_extension BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         RepeatedGroup_extension returnMe = result;
         result = null;
         return returnMe;
@@ -6378,6 +6450,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestRequired ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestRequired ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestRequired ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestRequired ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -6421,6 +6499,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestRequired BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestRequired returnMe = result;
         result = null;
         return returnMe;
@@ -7420,6 +7501,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestRequiredForeign ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestRequiredForeign ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestRequiredForeign ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestRequiredForeign ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -7463,6 +7550,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestRequiredForeign BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.repeatedMessage_.MakeReadOnly();
         TestRequiredForeign returnMe = result;
         result = null;
@@ -7718,6 +7808,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestForeignNested ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestForeignNested ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestForeignNested ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestForeignNested ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -7761,6 +7857,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestForeignNested BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestForeignNested returnMe = result;
         result = null;
         return returnMe;
@@ -7927,6 +8026,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestEmptyMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestEmptyMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestEmptyMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestEmptyMessage ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -7970,6 +8075,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestEmptyMessage BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestEmptyMessage returnMe = result;
         result = null;
         return returnMe;
@@ -8092,6 +8200,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestEmptyMessageWithExtensions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestEmptyMessageWithExtensions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestEmptyMessageWithExtensions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestEmptyMessageWithExtensions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -8135,6 +8249,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestEmptyMessageWithExtensions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestEmptyMessageWithExtensions returnMe = result;
         result = null;
         return returnMe;
@@ -8286,6 +8403,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestReallyLargeTagNumber ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestReallyLargeTagNumber ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestReallyLargeTagNumber ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestReallyLargeTagNumber ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -8329,6 +8452,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestReallyLargeTagNumber BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestReallyLargeTagNumber returnMe = result;
         result = null;
         return returnMe;
@@ -8529,6 +8655,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestRecursiveMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestRecursiveMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestRecursiveMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestRecursiveMessage ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -8572,6 +8704,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestRecursiveMessage BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestRecursiveMessage returnMe = result;
         result = null;
         return returnMe;
@@ -8779,6 +8914,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMutualRecursionA ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMutualRecursionA ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMutualRecursionA ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMutualRecursionA ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -8822,6 +8963,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMutualRecursionA BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMutualRecursionA returnMe = result;
         result = null;
         return returnMe;
@@ -9020,6 +9164,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMutualRecursionB ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMutualRecursionB ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMutualRecursionB ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMutualRecursionB ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -9063,6 +9213,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMutualRecursionB BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMutualRecursionB returnMe = result;
         result = null;
         return returnMe;
@@ -9294,6 +9447,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static Foo ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static Foo ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static Foo ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static Foo ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -9337,6 +9496,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override Foo BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             Foo returnMe = result;
             result = null;
             return returnMe;
@@ -9496,6 +9658,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static Bar ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static Bar ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static Bar ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static Bar ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -9539,6 +9707,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override Bar BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             Bar returnMe = result;
             result = null;
             return returnMe;
@@ -9711,6 +9882,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestDupFieldNumber ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestDupFieldNumber ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestDupFieldNumber ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestDupFieldNumber ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -9754,6 +9931,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestDupFieldNumber BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestDupFieldNumber returnMe = result;
         result = null;
         return returnMe;
@@ -10060,6 +10240,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static NestedMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static NestedMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static NestedMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static NestedMessage ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -10103,6 +10289,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override NestedMessage BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             result.nestedmessageRepeatedInt32_.MakeReadOnly();
             result.nestedmessageRepeatedForeignmessage_.MakeReadOnly();
             NestedMessage returnMe = result;
@@ -10300,6 +10489,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestNestedMessageHasBits ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestNestedMessageHasBits ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestNestedMessageHasBits ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestNestedMessageHasBits ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -10343,6 +10538,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestNestedMessageHasBits BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestNestedMessageHasBits returnMe = result;
         result = null;
         return returnMe;
@@ -10750,6 +10948,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestCamelCaseFieldNames ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestCamelCaseFieldNames ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestCamelCaseFieldNames ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestCamelCaseFieldNames ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -10793,6 +10997,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestCamelCaseFieldNames BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.repeatedPrimitiveField_.MakeReadOnly();
         result.repeatedStringField_.MakeReadOnly();
         result.repeatedEnumField_.MakeReadOnly();
@@ -11380,6 +11587,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestFieldOrderings ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestFieldOrderings ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestFieldOrderings ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestFieldOrderings ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -11423,6 +11636,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestFieldOrderings BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestFieldOrderings returnMe = result;
         result = null;
         return returnMe;
@@ -11714,6 +11930,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestExtremeDefaultValues ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestExtremeDefaultValues ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestExtremeDefaultValues ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestExtremeDefaultValues ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -11757,6 +11979,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestExtremeDefaultValues BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestExtremeDefaultValues returnMe = result;
         result = null;
         return returnMe;
@@ -12435,6 +12660,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestPackedTypes ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestPackedTypes ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestPackedTypes ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestPackedTypes ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -12478,6 +12709,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestPackedTypes BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.packedInt32_.MakeReadOnly();
         result.packedInt64_.MakeReadOnly();
         result.packedUint32_.MakeReadOnly();
@@ -13154,6 +13388,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestPackedExtensions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestPackedExtensions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestPackedExtensions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestPackedExtensions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -13197,6 +13437,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestPackedExtensions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestPackedExtensions returnMe = result;
         result = null;
         return returnMe;
@@ -13316,6 +13559,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static FooRequest ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static FooRequest ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static FooRequest ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static FooRequest ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -13359,6 +13608,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override FooRequest BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         FooRequest returnMe = result;
         result = null;
         return returnMe;
@@ -13477,6 +13729,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static FooResponse ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static FooResponse ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static FooResponse ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static FooResponse ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -13520,6 +13778,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override FooResponse BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         FooResponse returnMe = result;
         result = null;
         return returnMe;
@@ -13638,6 +13899,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static BarRequest ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static BarRequest ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static BarRequest ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static BarRequest ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -13681,6 +13948,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override BarRequest BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         BarRequest returnMe = result;
         result = null;
         return returnMe;
@@ -13799,6 +14069,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static BarResponse ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static BarResponse ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static BarResponse ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static BarResponse ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -13842,6 +14118,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override BarResponse BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         BarResponse returnMe = result;
         result = null;
         return returnMe;
diff --git a/src/ProtocolBuffers.Test/WireFormatTest.cs b/src/ProtocolBuffers.Test/WireFormatTest.cs
index b519d7a7..2d558af5 100644
--- a/src/ProtocolBuffers.Test/WireFormatTest.cs
+++ b/src/ProtocolBuffers.Test/WireFormatTest.cs
@@ -29,6 +29,7 @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+using System.IO;
 using System.Reflection;
 using Google.ProtocolBuffers.Descriptors;
 using Google.ProtocolBuffers.TestProtos;
@@ -99,6 +100,23 @@ namespace Google.ProtocolBuffers {
     }
 
     [Test]
+    public void SerializeDelimited() {
+      MemoryStream stream = new MemoryStream();
+      TestUtil.GetAllSet().WriteDelimitedTo(stream);
+      stream.WriteByte(12);
+      TestUtil.GetPackedSet().WriteDelimitedTo(stream);
+      stream.WriteByte(34);
+
+      stream.Position = 0;
+
+      TestUtil.AssertAllFieldsSet(TestAllTypes.ParseDelimitedFrom(stream));
+      Assert.AreEqual(12, stream.ReadByte());
+      TestUtil.AssertPackedFieldsSet(TestPackedTypes.ParseDelimitedFrom(stream));
+      Assert.AreEqual(34, stream.ReadByte());
+      Assert.AreEqual(-1, stream.ReadByte());
+    }
+
+    [Test]
     public void ParseExtensions() {
       // TestAllTypes and TestAllExtensions should have compatible wire formats,
       // so if we serealize a TestAllTypes then parse it as TestAllExtensions
@@ -133,7 +151,7 @@ namespace Google.ProtocolBuffers {
       Assert.AreEqual(TestUtil.GetAllSet().SerializedSize, TestUtil.GetAllExtensionsSet().SerializedSize);
     }
 
-    private void AssertFieldsInOrder(ByteString data) {
+    private static void AssertFieldsInOrder(ByteString data) {
       CodedInputStream input = data.CreateCodedInput();
       uint previousTag = 0;
 
diff --git a/src/ProtocolBuffers/AbstractBuilder.cs b/src/ProtocolBuffers/AbstractBuilder.cs
index 780d4213..d7831cd1 100644
--- a/src/ProtocolBuffers/AbstractBuilder.cs
+++ b/src/ProtocolBuffers/AbstractBuilder.cs
@@ -225,6 +225,16 @@ namespace Google.ProtocolBuffers {
       return ThisBuilder;
     }
 
+    public TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry) {
+      int size = CodedInputStream.ReadRawVarint32(input);
+      Stream limitedStream = new LimitedInputStream(input, size);
+      return MergeFrom(limitedStream, extensionRegistry);
+    }
+
+    public TBuilder MergeDelimitedFrom(Stream input) {
+      return MergeDelimitedFrom(input, ExtensionRegistry.Empty);
+    }
+
     public virtual IBuilder SetField(FieldDescriptor field, object value) {
       this[field] = value;
       return ThisBuilder;
@@ -234,5 +244,70 @@ namespace Google.ProtocolBuffers {
       this[field, index] = value;
       return ThisBuilder;
     }
+
+    /// <summary>
+    /// Stream implementation which proxies another stream, only allowing a certain amount
+    /// of data to be read. Note that this is only used to read delimited streams, so it
+    /// doesn't attempt to implement everything.
+    /// </summary>
+    private class LimitedInputStream : Stream {
+
+      private readonly Stream proxied;
+      private int bytesLeft;
+
+      internal LimitedInputStream(Stream proxied, int size) {
+        this.proxied = proxied;
+        bytesLeft = size;
+      }
+
+      public override bool CanRead {
+        get { return true; }
+      }
+
+      public override bool CanSeek {
+        get { return false; }
+      }
+
+      public override bool CanWrite {
+        get { return false; }
+      }
+
+      public override void Flush() {
+      }
+
+      public override long Length {
+        get { throw new NotImplementedException(); }
+      }
+
+      public override long Position {
+        get {
+          throw new NotImplementedException();
+        }
+        set {
+          throw new NotImplementedException();
+        }
+      }
+
+      public override int Read(byte[] buffer, int offset, int count) {
+        if (bytesLeft > 0) {
+          int bytesRead = proxied.Read(buffer, offset, Math.Min(bytesLeft, count));
+          bytesLeft -= bytesRead;
+          return bytesRead;
+        }
+        return 0;
+      }
+
+      public override long Seek(long offset, SeekOrigin origin) {
+        throw new NotImplementedException();
+      }
+
+      public override void SetLength(long value) {
+        throw new NotImplementedException();
+      }
+
+      public override void Write(byte[] buffer, int offset, int count) {
+        throw new NotImplementedException();
+      }
+    }
   }
 }
diff --git a/src/ProtocolBuffers/AbstractMessage.cs b/src/ProtocolBuffers/AbstractMessage.cs
index 27cd77ba..760b4678 100644
--- a/src/ProtocolBuffers/AbstractMessage.cs
+++ b/src/ProtocolBuffers/AbstractMessage.cs
@@ -205,6 +205,13 @@ namespace Google.ProtocolBuffers {
       codedOutput.Flush();
     }
 
+    public void WriteDelimitedTo(Stream output) {
+      CodedOutputStream codedOutput = CodedOutputStream.CreateInstance(output);
+      codedOutput.WriteRawVarint32((uint) SerializedSize);
+      WriteTo(codedOutput);
+      codedOutput.Flush();
+    }
+
     public override bool Equals(object other) {
       if (other == this) {
         return true;
diff --git a/src/ProtocolBuffers/CodedInputStream.cs b/src/ProtocolBuffers/CodedInputStream.cs
index 59d51061..89d8e33e 100644
--- a/src/ProtocolBuffers/CodedInputStream.cs
+++ b/src/ProtocolBuffers/CodedInputStream.cs
@@ -141,7 +141,7 @@ namespace Google.ProtocolBuffers {
     /// zero is not a valid tag number.
     /// </summary>
     public uint ReadTag() {
-      if (bufferPos == bufferSize && !RefillBuffer(false)) {
+      if (IsAtEnd) {
         lastTag = 0;
         return 0;
       }
@@ -458,6 +458,41 @@ namespace Google.ProtocolBuffers {
     }
 
     /// <summary>
+    /// Reads a varint from the input one byte at a time, so that it does not
+    /// read any bytes after the end of the varint. If you simply wrapped the
+    /// stream in a CodedInputStream and used ReadRawVarint32(Stream)}
+    /// then you would probably end up reading past the end of the varint since
+    /// CodedInputStream buffers its input.
+    /// </summary>
+    /// <param name="input"></param>
+    /// <returns></returns>
+    internal static int ReadRawVarint32(Stream input) {
+      int result = 0;
+      int offset = 0;
+      for (; offset < 32; offset += 7) {
+        int b = input.ReadByte();
+        if (b == -1) {
+          throw InvalidProtocolBufferException.TruncatedMessage();
+        }
+        result |= (b & 0x7f) << offset;
+        if ((b & 0x80) == 0) {
+          return result;
+        }
+      }
+      // Keep reading up to 64 bits.
+      for (; offset < 64; offset += 7) {
+        int b = input.ReadByte();
+        if (b == -1) {
+          throw InvalidProtocolBufferException.TruncatedMessage();
+        }
+        if ((b & 0x80) == 0) {
+          return result;
+        }
+      }
+      throw InvalidProtocolBufferException.MalformedVarint();
+    }
+
+    /// <summary>
     /// Read a raw varint from the stream.
     /// </summary>
     public ulong ReadRawVarint64() {
@@ -555,6 +590,9 @@ namespace Google.ProtocolBuffers {
     /// as you can without harming your app's functionality.  Note that
     /// size limits only apply when reading from an InputStream, not
     /// when constructed around a raw byte array (nor with ByteString.NewCodedInput).
+    /// If you want to read several messages from a single CodedInputStream, you
+    /// can call ResetSizeCounter() after each message to avoid hitting the
+    /// size limit.
     /// </remarks>
     public int SetSizeLimit(int limit) {
       if (limit < 0) {
@@ -567,6 +605,13 @@ namespace Google.ProtocolBuffers {
 
     #region Internal reading and buffer management
     /// <summary>
+    /// Resets the current size counter to zero (see SetSizeLimit).
+    /// </summary>
+    public void ResetSizeCounter() {
+      totalBytesRetired = 0;
+    }
+
+    /// <summary>
     /// Sets currentLimit to (current position) + byteLimit. This is called
     /// when descending into a length-delimited embedded message. The previous
     /// limit is returned.
@@ -621,6 +666,17 @@ namespace Google.ProtocolBuffers {
         return currentAbsolutePosition >= currentLimit;
       }
     }
+
+    /// <summary>
+    /// Returns true if the stream has reached the end of the input. This is the
+    /// case if either the end of the underlying input source has been reached or
+    /// the stream has reached a limit created using PushLimit.
+    /// </summary>
+    public bool IsAtEnd {
+      get {
+        return bufferPos == bufferSize && !RefillBuffer(false);
+      }
+    }
     
     /// <summary>
     /// Called when buffer is empty to read more bytes from the
@@ -649,6 +705,9 @@ namespace Google.ProtocolBuffers {
 
       bufferPos = 0;
       bufferSize = (input == null) ? 0 : input.Read(buffer, 0, buffer.Length);
+      if (bufferSize < 0) {
+        throw new InvalidOperationException("Stream.Read returned a negative count");
+      }
       if (bufferSize == 0) {
         if (mustSucceed) {
           throw InvalidProtocolBufferException.TruncatedMessage();
@@ -847,7 +906,7 @@ namespace Google.ProtocolBuffers {
         throw InvalidProtocolBufferException.TruncatedMessage();
       }
 
-      if (size < bufferSize - bufferPos) {
+      if (size <= bufferSize - bufferPos) {
         // We have all the bytes we need already.
         bufferPos += size;
       } else {
@@ -863,8 +922,9 @@ namespace Google.ProtocolBuffers {
           if (input == null) {
             throw InvalidProtocolBufferException.TruncatedMessage();
           }
-          input.Seek(size - pos, SeekOrigin.Current);
-          if (input.Position > input.Length) {
+          long previousPosition = input.Position;
+          input.Position += size - pos;
+          if (input.Position != previousPosition + size - pos) {
             throw InvalidProtocolBufferException.TruncatedMessage();
           }
           totalBytesRetired += size - pos;
diff --git a/src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs b/src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs
index c7f04e5e..aa7aa6d7 100644
--- a/src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs
+++ b/src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs
@@ -143,6 +143,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static CSharpFileOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CSharpFileOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CSharpFileOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CSharpFileOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -186,6 +192,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override CSharpFileOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CSharpFileOptions returnMe = result;
         result = null;
         return returnMe;
@@ -336,6 +345,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static CSharpFieldOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CSharpFieldOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CSharpFieldOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CSharpFieldOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -379,6 +394,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override CSharpFieldOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CSharpFieldOptions returnMe = result;
         result = null;
         return returnMe;
diff --git a/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs b/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
index ddd2f504..e8138877 100644
--- a/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
+++ b/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
@@ -273,6 +273,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static FileDescriptorSet ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static FileDescriptorSet ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static FileDescriptorSet ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static FileDescriptorSet ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -316,6 +322,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override FileDescriptorSet BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.file_.MakeReadOnly();
         FileDescriptorSet returnMe = result;
         result = null;
@@ -642,6 +651,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static FileDescriptorProto ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static FileDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static FileDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static FileDescriptorProto ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -685,6 +700,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override FileDescriptorProto BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.dependency_.MakeReadOnly();
         result.messageType_.MakeReadOnly();
         result.enumType_.MakeReadOnly();
@@ -1187,6 +1205,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         public static ExtensionRange ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static ExtensionRange ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static ExtensionRange ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static ExtensionRange ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -1230,6 +1254,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
           }
           
           public override ExtensionRange BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             ExtensionRange returnMe = result;
             result = null;
             return returnMe;
@@ -1516,6 +1543,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static DescriptorProto ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static DescriptorProto ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static DescriptorProto ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static DescriptorProto ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1559,6 +1592,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override DescriptorProto BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.field_.MakeReadOnly();
         result.extension_.MakeReadOnly();
         result.nestedType_.MakeReadOnly();
@@ -2154,6 +2190,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static FieldDescriptorProto ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static FieldDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static FieldDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static FieldDescriptorProto ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -2197,6 +2239,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override FieldDescriptorProto BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         FieldDescriptorProto returnMe = result;
         result = null;
         return returnMe;
@@ -2614,6 +2659,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static EnumDescriptorProto ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static EnumDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static EnumDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static EnumDescriptorProto ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -2657,6 +2708,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override EnumDescriptorProto BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.value_.MakeReadOnly();
         EnumDescriptorProto returnMe = result;
         result = null;
@@ -2948,6 +3002,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static EnumValueDescriptorProto ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static EnumValueDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static EnumValueDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static EnumValueDescriptorProto ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -2991,6 +3051,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override EnumValueDescriptorProto BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         EnumValueDescriptorProto returnMe = result;
         result = null;
         return returnMe;
@@ -3264,6 +3327,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static ServiceDescriptorProto ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ServiceDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ServiceDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ServiceDescriptorProto ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -3307,6 +3376,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override ServiceDescriptorProto BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.method_.MakeReadOnly();
         ServiceDescriptorProto returnMe = result;
         result = null;
@@ -3614,6 +3686,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static MethodDescriptorProto ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static MethodDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static MethodDescriptorProto ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static MethodDescriptorProto ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -3657,6 +3735,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override MethodDescriptorProto BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         MethodDescriptorProto returnMe = result;
         result = null;
         return returnMe;
@@ -4000,6 +4081,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static FileOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static FileOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static FileOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static FileOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -4043,6 +4130,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override FileOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.uninterpretedOption_.MakeReadOnly();
         FileOptions returnMe = result;
         result = null;
@@ -4361,6 +4451,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static MessageOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static MessageOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static MessageOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static MessageOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -4404,6 +4500,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override MessageOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.uninterpretedOption_.MakeReadOnly();
         MessageOptions returnMe = result;
         result = null;
@@ -4679,6 +4778,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static FieldOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static FieldOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static FieldOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static FieldOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -4722,6 +4827,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override FieldOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.uninterpretedOption_.MakeReadOnly();
         FieldOptions returnMe = result;
         result = null;
@@ -4998,6 +5106,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static EnumOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static EnumOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static EnumOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static EnumOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -5041,6 +5155,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override EnumOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.uninterpretedOption_.MakeReadOnly();
         EnumOptions returnMe = result;
         result = null;
@@ -5233,6 +5350,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static EnumValueOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static EnumValueOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static EnumValueOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static EnumValueOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -5276,6 +5399,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override EnumValueOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.uninterpretedOption_.MakeReadOnly();
         EnumValueOptions returnMe = result;
         result = null;
@@ -5468,6 +5594,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static ServiceOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ServiceOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ServiceOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ServiceOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -5511,6 +5643,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override ServiceOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.uninterpretedOption_.MakeReadOnly();
         ServiceOptions returnMe = result;
         result = null;
@@ -5703,6 +5838,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static MethodOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static MethodOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static MethodOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static MethodOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -5746,6 +5887,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override MethodOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.uninterpretedOption_.MakeReadOnly();
         MethodOptions returnMe = result;
         result = null;
@@ -5971,6 +6115,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
         public static NamePart ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static NamePart ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static NamePart ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static NamePart ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -6014,6 +6164,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
           }
           
           public override NamePart BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             NamePart returnMe = result;
             result = null;
             return returnMe;
@@ -6265,6 +6418,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static UninterpretedOption ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static UninterpretedOption ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static UninterpretedOption ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static UninterpretedOption ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -6308,6 +6467,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override UninterpretedOption BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.name_.MakeReadOnly();
         UninterpretedOption returnMe = result;
         result = null;
diff --git a/src/ProtocolBuffers/IBuilder.cs b/src/ProtocolBuffers/IBuilder.cs
index 6b01afb9..36db1f11 100644
--- a/src/ProtocolBuffers/IBuilder.cs
+++ b/src/ProtocolBuffers/IBuilder.cs
@@ -247,6 +247,20 @@ namespace Google.ProtocolBuffers {
     /// Merge some unknown fields into the set for this message.
     /// </summary>
     TBuilder MergeUnknownFields(UnknownFieldSet unknownFields);
+    
+    /// <summary>
+    /// Like MergeFrom(Stream), but does not read until the end of the file.
+    /// Instead, the size of the message (encoded as a varint) is read first,
+    /// then the message data. Use Message.WriteDelimitedTo(Stream) to
+    /// write messages in this format.
+    /// </summary>
+    /// <param name="input"></param>
+    TBuilder MergeDelimitedFrom(Stream input);
+
+    /// <summary>
+    /// Like MergeDelimitedFrom(Stream) but supporting extensions.
+    /// </summary>
+    TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry);
 
     #region Convenience methods
     /// <summary>
@@ -283,8 +297,9 @@ namespace Google.ProtocolBuffers {
     /// MergeFrom(CodedInputStream). Note that this method always reads
     /// the entire input (unless it throws an exception). If you want it to
     /// stop earlier, you will need to wrap the input in a wrapper
-    /// stream which limits reading. Despite usually reading the entire
-    /// stream, this method never closes the stream.
+    /// stream which limits reading. Or, use IMessage.WriteDelimitedTo(Stream)
+    /// to write your message and MmergeDelimitedFrom(Stream) to read it.
+    /// Despite usually reading the entire stream, this method never closes the stream. 
     /// </summary>
     TBuilder MergeFrom(Stream input);
 
diff --git a/src/ProtocolBuffers/IMessage.cs b/src/ProtocolBuffers/IMessage.cs
index e87bb52c..98b18a35 100644
--- a/src/ProtocolBuffers/IMessage.cs
+++ b/src/ProtocolBuffers/IMessage.cs
@@ -113,10 +113,27 @@ namespace Google.ProtocolBuffers {
     /// Serializes the message and writes it to the given output stream.
     /// This does not flush or close the stream.
     /// </summary>
-    /// <param name="output"></param>
+    /// <remarks>
+    /// Protocol Buffers are not self-delimiting. Therefore, if you write
+    /// any more data to the stream after the message, you must somehow ensure
+    /// that the parser on the receiving end does not interpret this as being
+    /// part of the protocol message. One way of doing this is by writing the size
+    /// of the message before the data, then making sure you limit the input to
+    /// that size when receiving the data. Alternatively, use WriteDelimitedTo(Stream).
+    /// </remarks>
     void WriteTo(CodedOutputStream output);
 
     /// <summary>
+    /// Like WriteTo(Stream) but writes the size of the message as a varint before
+    /// writing the data. This allows more data to be written to the stream after the
+    /// message without the need to delimit the message data yourself. Use 
+    /// IBuilder.MergeDelimitedFrom(Stream) or the static method
+    /// YourMessageType.ParseDelimitedFrom(Stream) to parse messages written by this method.
+    /// </summary>
+    /// <param name="output"></param>
+    void WriteDelimitedTo(Stream output);
+
+    /// <summary>
     /// Returns the number of bytes required to encode this message.
     /// The result is only computed on the first call and memoized after that.
     /// </summary>
diff --git a/src/ProtocolBuffers/MessageStreamIterator.cs b/src/ProtocolBuffers/MessageStreamIterator.cs
index 7239e9ab..cb1ead1a 100644
--- a/src/ProtocolBuffers/MessageStreamIterator.cs
+++ b/src/ProtocolBuffers/MessageStreamIterator.cs
@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Text;
 using System.Collections;
 using System.IO;
 using System.Reflection;
diff --git a/src/ProtocolBuffers/MessageStreamWriter.cs b/src/ProtocolBuffers/MessageStreamWriter.cs
index 8cd0fa3a..6f7c7c59 100644
--- a/src/ProtocolBuffers/MessageStreamWriter.cs
+++ b/src/ProtocolBuffers/MessageStreamWriter.cs
@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
 using System.IO;
 
 namespace Google.ProtocolBuffers {