merged issue-22

7 files changed, 68 insertions, 15 deletions

diff --git a/src/ProtoGen/EnumFieldGenerator.cs b/src/ProtoGen/EnumFieldGenerator.cs
index 78384fdd..8d70bc67 100644
--- a/src/ProtoGen/EnumFieldGenerator.cs
+++ b/src/ProtoGen/EnumFieldGenerator.cs
@@ -72,12 +72,14 @@ namespace Google.ProtocolBuffers.ProtoGen
             writer.WriteLine("}");

             AddPublicMemberAttributes(writer);

             writer.WriteLine("public Builder Set{0}({1} value) {{", PropertyName, TypeName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.has{0} = true;", PropertyName);

             writer.WriteLine("  result.{0}_ = value;", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Clear{0}() {{", PropertyName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.has{0} = false;", PropertyName);

             writer.WriteLine("  result.{0}_ = {1};", Name, DefaultValue);

             writer.WriteLine("  return this;");

diff --git a/src/ProtoGen/MessageFieldGenerator.cs b/src/ProtoGen/MessageFieldGenerator.cs
index 8e4bef5b..8e2691ee 100644
--- a/src/ProtoGen/MessageFieldGenerator.cs
+++ b/src/ProtoGen/MessageFieldGenerator.cs
@@ -73,6 +73,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Set{0}({1} value) {{", PropertyName, TypeName);

             AddNullCheck(writer);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.has{0} = true;", PropertyName);

             writer.WriteLine("  result.{0}_ = value;", Name);

             writer.WriteLine("  return this;");

@@ -80,6 +81,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Set{0}({1}.Builder builderForValue) {{", PropertyName, TypeName);

             AddNullCheck(writer, "builderForValue");

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.has{0} = true;", PropertyName);

             writer.WriteLine("  result.{0}_ = builderForValue.Build();", Name);

             writer.WriteLine("  return this;");

@@ -87,6 +89,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Merge{0}({1} value) {{", PropertyName, TypeName);

             AddNullCheck(writer);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  if (result.has{0} &&", PropertyName);

             writer.WriteLine("      result.{0}_ != {1}) {{", Name, DefaultValue);

             writer.WriteLine("      result.{0}_ = {1}.CreateBuilder(result.{0}_).MergeFrom(value).BuildPartial();", Name,

@@ -99,6 +102,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Clear{0}() {{", PropertyName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.has{0} = false;", PropertyName);

             writer.WriteLine("  result.{0}_ = {1};", Name, DefaultValue);

             writer.WriteLine("  return this;");

diff --git a/src/ProtoGen/MessageGenerator.cs b/src/ProtoGen/MessageGenerator.cs
index c8b2087f..89c4aaec 100644
--- a/src/ProtoGen/MessageGenerator.cs
+++ b/src/ProtoGen/MessageGenerator.cs
@@ -556,7 +556,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             writer.WriteLine("public override Builder ToBuilder() { return CreateBuilder(this); }");

             writer.WriteLine("public override Builder CreateBuilderForType() { return new Builder(); }");

             writer.WriteLine("public static Builder CreateBuilder({0} prototype) {{", ClassName);

-            writer.WriteLine("  return (Builder) new Builder().MergeFrom(prototype);");

+            writer.WriteLine("  return new Builder(prototype);");

             writer.WriteLine("}");

             writer.WriteLine();

             if (Descriptor.File.CSharpOptions.AddSerializable)

@@ -591,21 +591,52 @@ namespace Google.ProtocolBuffers.ProtoGen
 

         private void GenerateCommonBuilderMethods(TextGenerator writer)

         {

-            writer.WriteLine("public Builder() {{}}", ClassAccessLevel);

+            //default constructor

+            writer.WriteLine("public Builder() {");

+            //Durring static initialization of message, DefaultInstance is expected to return null.

+            writer.WriteLine("  result = DefaultInstance ?? new {0}();", ClassName);

+            writer.WriteLine("  builderIsReadOnly = result == DefaultInstance;");

+            writer.WriteLine("}");

+            //clone constructor

+            writer.WriteLine("internal Builder({0} cloneFrom) {{", ClassName);

+            writer.WriteLine("  result = cloneFrom;");

+            writer.WriteLine("  builderIsReadOnly = true;");

+            writer.WriteLine("}");

+            writer.WriteLine();

+            writer.WriteLine("bool builderIsReadOnly;");

+            writer.WriteLine("{0} result;", ClassName);

+            writer.WriteLine();

+            writer.WriteLine("private {0} PrepareBuilder() {{", ClassName);

+            writer.WriteLine("  if (builderIsReadOnly) {");

+            writer.WriteLine("    {0} original = result;", ClassName);

+            writer.WriteLine("    result = new {0}();", ClassName);

+            writer.WriteLine("    builderIsReadOnly = false;");

+            writer.WriteLine("    MergeFrom(original);");

+            writer.WriteLine("  }");

+            writer.WriteLine("  return result;");

+            writer.WriteLine("}");

             writer.WriteLine();

-            writer.WriteLine("{0} result = new {0}();", ClassName);

+            writer.WriteLine("public override bool IsInitialized {");

+            writer.WriteLine("  get { return result.IsInitialized; }");

+            writer.WriteLine("}");

             writer.WriteLine();

             writer.WriteLine("protected override {0} MessageBeingBuilt {{", ClassName);

-            writer.WriteLine("  get { return result; }");

+            writer.WriteLine("  get { return PrepareBuilder(); }");

             writer.WriteLine("}");

             writer.WriteLine();

+            //Not actually expecting that DefaultInstance would ever be null here; however, we will ensure it does not break

             writer.WriteLine("public override Builder Clear() {");

-            writer.WriteLine("  result = new {0}();", ClassName);

+            writer.WriteLine("  result = DefaultInstance ?? new {0}();", ClassName);

+            writer.WriteLine("  builderIsReadOnly = true;");

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             writer.WriteLine();

             writer.WriteLine("public override Builder Clone() {");

-            writer.WriteLine("  return new Builder().MergeFrom(result);");

+            writer.WriteLine("  if (builderIsReadOnly) {");

+            writer.WriteLine("    return new Builder(result);");

+            writer.WriteLine("  } else {");

+            writer.WriteLine("    return new Builder().MergeFrom(result);");

+            writer.WriteLine("  }");

             writer.WriteLine("}");

             writer.WriteLine();

             if (!UseLiteRuntime)

@@ -622,17 +653,15 @@ 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("if (builderIsReadOnly) {");

+            writer.WriteLine("  return result;");

             writer.WriteLine("}");

             foreach (FieldDescriptor field in Descriptor.Fields)

             {

                 CreateFieldGenerator(field).GenerateBuildingCode(writer);

             }

-            writer.WriteLine("{0} returnMe = result;", ClassName);

-            writer.WriteLine("result = null;");

-            writer.WriteLine("return returnMe;");

+            writer.WriteLine("builderIsReadOnly = true;");

+            writer.WriteLine("return result;");

             writer.Outdent();

             writer.WriteLine("}");

             writer.WriteLine();

@@ -653,6 +682,7 @@ namespace Google.ProtocolBuffers.ProtoGen
                 // fields are set so we can skip the merge.

                 writer.Indent();

                 writer.WriteLine("if (other == {0}.DefaultInstance) return this;", FullClassName);

+                writer.WriteLine("PrepareBuilder();");

                 foreach (FieldDescriptor field in Descriptor.Fields)

                 {

                     CreateFieldGenerator(field).GenerateMergingCode(writer);

@@ -685,6 +715,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             writer.WriteLine(

                 "public override Builder MergeFrom(pb::ICodedInputStream input, pb::ExtensionRegistry extensionRegistry) {");

             writer.Indent();

+            writer.WriteLine("PrepareBuilder();");

             if (!UseLiteRuntime)

             {

                 writer.WriteLine("pb::UnknownFieldSet.Builder unknownFields = null;");

diff --git a/src/ProtoGen/PrimitiveFieldGenerator.cs b/src/ProtoGen/PrimitiveFieldGenerator.cs
index 0904ce22..69e0d4d9 100644
--- a/src/ProtoGen/PrimitiveFieldGenerator.cs
+++ b/src/ProtoGen/PrimitiveFieldGenerator.cs
@@ -74,12 +74,14 @@ namespace Google.ProtocolBuffers.ProtoGen
             AddPublicMemberAttributes(writer);

             writer.WriteLine("public Builder Set{0}({1} value) {{", PropertyName, TypeName);

             AddNullCheck(writer);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.has{0} = true;", PropertyName);

             writer.WriteLine("  result.{0}_ = value;", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Clear{0}() {{", PropertyName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.has{0} = false;", PropertyName);

             writer.WriteLine("  result.{0}_ = {1};", Name, DefaultValue);

             writer.WriteLine("  return this;");

diff --git a/src/ProtoGen/RepeatedEnumFieldGenerator.cs b/src/ProtoGen/RepeatedEnumFieldGenerator.cs
index fcda6564..aacee937 100644
--- a/src/ProtoGen/RepeatedEnumFieldGenerator.cs
+++ b/src/ProtoGen/RepeatedEnumFieldGenerator.cs
@@ -75,7 +75,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             // We return it via IPopsicleList so that collection initializers work more pleasantly.

             AddDeprecatedFlag(writer);

             writer.WriteLine("public pbc::IPopsicleList<{0}> {1}List {{", TypeName, PropertyName);

-            writer.WriteLine("  get {{ return result.{0}_; }}", Name);

+            writer.WriteLine("  get {{ return PrepareBuilder().{0}_; }}", Name);

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public int {0}Count {{", PropertyName);

@@ -87,21 +87,25 @@ namespace Google.ProtocolBuffers.ProtoGen
             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Set{0}(int index, {1} value) {{", PropertyName, TypeName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_[index] = value;", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Add{0}({1} value) {{", PropertyName, TypeName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Add(value);", Name, TypeName);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder AddRange{0}(scg::IEnumerable<{1}> values) {{", PropertyName, TypeName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Add(values);", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Clear{0}() {{", PropertyName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Clear();", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

diff --git a/src/ProtoGen/RepeatedMessageFieldGenerator.cs b/src/ProtoGen/RepeatedMessageFieldGenerator.cs
index d8f0a8eb..6cc1e631 100644
--- a/src/ProtoGen/RepeatedMessageFieldGenerator.cs
+++ b/src/ProtoGen/RepeatedMessageFieldGenerator.cs
@@ -71,7 +71,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             // We return it via IPopsicleList so that collection initializers work more pleasantly.

             AddDeprecatedFlag(writer);

             writer.WriteLine("public pbc::IPopsicleList<{0}> {1}List {{", TypeName, PropertyName);

-            writer.WriteLine("  get {{ return result.{0}_; }}", Name);

+            writer.WriteLine("  get {{ return PrepareBuilder().{0}_; }}", Name);

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public int {0}Count {{", PropertyName);

@@ -84,6 +84,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Set{0}(int index, {1} value) {{", PropertyName, TypeName);

             AddNullCheck(writer);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_[index] = value;", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

@@ -91,12 +92,14 @@ namespace Google.ProtocolBuffers.ProtoGen
             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Set{0}(int index, {1}.Builder builderForValue) {{", PropertyName, TypeName);

             AddNullCheck(writer, "builderForValue");

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_[index] = builderForValue.Build();", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Add{0}({1} value) {{", PropertyName, TypeName);

             AddNullCheck(writer);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Add(value);", Name, TypeName);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

@@ -104,16 +107,19 @@ namespace Google.ProtocolBuffers.ProtoGen
             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Add{0}({1}.Builder builderForValue) {{", PropertyName, TypeName);

             AddNullCheck(writer, "builderForValue");

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Add(builderForValue.Build());", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder AddRange{0}(scg::IEnumerable<{1}> values) {{", PropertyName, TypeName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Add(values);", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Clear{0}() {{", PropertyName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Clear();", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

diff --git a/src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs b/src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs
index 33f0fa2b..645dce5c 100644
--- a/src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs
+++ b/src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs
@@ -75,7 +75,7 @@ namespace Google.ProtocolBuffers.ProtoGen
             // We return it via IPopsicleList so that collection initializers work more pleasantly.

             AddPublicMemberAttributes(writer);

             writer.WriteLine("public pbc::IPopsicleList<{0}> {1}List {{", TypeName, PropertyName);

-            writer.WriteLine("  get {{ return result.{0}_; }}", Name);

+            writer.WriteLine("  get {{ return PrepareBuilder().{0}_; }}", Name);

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public int {0}Count {{", PropertyName);

@@ -88,22 +88,26 @@ namespace Google.ProtocolBuffers.ProtoGen
             AddPublicMemberAttributes(writer);

             writer.WriteLine("public Builder Set{0}(int index, {1} value) {{", PropertyName, TypeName);

             AddNullCheck(writer);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_[index] = value;", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddPublicMemberAttributes(writer);

             writer.WriteLine("public Builder Add{0}({1} value) {{", PropertyName, TypeName);

             AddNullCheck(writer);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Add(value);", Name, TypeName);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddPublicMemberAttributes(writer);

             writer.WriteLine("public Builder AddRange{0}(scg::IEnumerable<{1}> values) {{", PropertyName, TypeName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Add(values);", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");

             AddDeprecatedFlag(writer);

             writer.WriteLine("public Builder Clear{0}() {{", PropertyName);

+            writer.WriteLine("  PrepareBuilder();");

             writer.WriteLine("  result.{0}_.Clear();", Name);

             writer.WriteLine("  return this;");

             writer.WriteLine("}");