Merge pull request #4131 from pherl/merge

Merge 3.5.x branch into master

55 files changed, 853 insertions, 218 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index ea3252bb..c7c42916 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,34 @@
+2017-12-20 version 3.5.1 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
+  Planned Future Changes
+  * Make C++ implementation C++11 only: we plan to require C++11 to build
+    protobuf code starting from 3.6.0 release. Please join this github issue:
+    https://github.com/google/protobuf/issues/2780 to provide your feedback.
+
+  protoc
+  * Fixed a bug introduced in 3.5.0 and protoc in Windows now accepts non-ascii
+    characters in paths again.
+
+  C++
+  * Removed several usages of C++11 features in the code base.
+  * Fixed some compiler warnings.
+
+  PHP
+  * Fixed memory leak in C-extension implementation.
+  * Added discardUnknokwnFields API.
+  * Removed duplicatd typedef in C-extension headers.
+  * Avoided calling private php methods (timelib_update_ts).
+  * Fixed Any.php to use fully-qualified name for DescriptorPool.
+
+  Ruby
+  * Added Google_Protobuf_discard_unknown for discarding unknown fields in
+    messages.
+
+  C#
+  * Unknown fields are now preserved by default.
+  * Floating point values are now bitwise compared, affecting message equality
+    check and Contains() API in map and repeated fields.
+
+
 2017-11-13 version 3.5.0 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
   Planned Future Changes
   * Make C++ implementation C++11 only: we plan to require C++11 to build
diff --git a/Makefile.am b/Makefile.am
index 74fab324..d392429f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -926,6 +926,7 @@ ruby_EXTRA_DIST=                                                             \
   ruby/src/main/java/google/ProtobufJavaService.java                         \
   ruby/src/main/sentinel.proto                                               \
   ruby/tests/basic.rb                                                        \
+  ruby/tests/encode_decode_test.rb                                           \
   ruby/tests/gc_test.rb                                                      \
   ruby/tests/repeated_field_test.rb                                          \
   ruby/tests/stress.rb                                                       \
diff --git a/Protobuf.podspec b/Protobuf.podspec
index b65ac43c..84a37996 100644
--- a/Protobuf.podspec
+++ b/Protobuf.podspec
@@ -5,7 +5,7 @@
 # dependent projects use the :git notation to refer to the library.
 Pod::Spec.new do |s|
   s.name     = 'Protobuf'
-  s.version  = '3.5.0'
+  s.version  = '3.5.1'
   s.summary  = 'Protocol Buffers v.3 runtime library for Objective-C.'
   s.homepage = 'https://github.com/google/protobuf'
   s.license  = '3-Clause BSD License'
diff --git a/configure.ac b/configure.ac
index 51ce5be0..faa1cdc3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,7 @@ AC_PREREQ(2.59)
 # In the SVN trunk, the version should always be the next anticipated release
 # version with the "-pre" suffix.  (We used to use "-SNAPSHOT" but this pushed
 # the size of one file name in the dist tarfile over the 99-char limit.)
-AC_INIT([Protocol Buffers],[3.5.0],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[3.5.1],[protobuf@googlegroups.com],[protobuf])
 
 AM_MAINTAINER_MODE([enable])
 
diff --git a/csharp/Google.Protobuf.Tools.nuspec b/csharp/Google.Protobuf.Tools.nuspec
index 7cd9dc59..62eb3b58 100644
--- a/csharp/Google.Protobuf.Tools.nuspec
+++ b/csharp/Google.Protobuf.Tools.nuspec
@@ -5,7 +5,7 @@
     <title>Google Protocol Buffers tools</title>
     <summary>Tools for Protocol Buffers - Google's data interchange format.</summary>
     <description>See project site for more info.</description>
-    <version>3.5.0</version>
+    <version>3.5.1</version>
     <authors>Google Inc.</authors>
     <owners>protobuf-packages</owners>
     <licenseUrl>https://github.com/google/protobuf/blob/master/LICENSE</licenseUrl>
diff --git a/csharp/src/Google.Protobuf/Google.Protobuf.csproj b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
index bf7a5e7d..4df0bda6 100644
--- a/csharp/src/Google.Protobuf/Google.Protobuf.csproj
+++ b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
@@ -4,7 +4,7 @@
     <Description>C# runtime library for Protocol Buffers - Google's data interchange format.</Description>
     <Copyright>Copyright 2015, Google Inc.</Copyright>
     <AssemblyTitle>Google Protocol Buffers</AssemblyTitle>
-    <VersionPrefix>3.5.0</VersionPrefix>
+    <VersionPrefix>3.5.1</VersionPrefix>
     <Authors>Google Inc.</Authors>
     <TargetFrameworks>netstandard1.0;net45</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
diff --git a/java/core/pom.xml b/java/core/pom.xml
index 95f6f7ff..4b65e72e 100644
--- a/java/core/pom.xml
+++ b/java/core/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.5.0</version>
+    <version>3.5.1</version>
   </parent>
 
   <artifactId>protobuf-java</artifactId>
diff --git a/java/pom.xml b/java/pom.xml
index fa0d0e13..6e339d7f 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -11,7 +11,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-parent</artifactId>
-  <version>3.5.0</version>
+  <version>3.5.1</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [Parent]</name>
diff --git a/java/util/pom.xml b/java/util/pom.xml
index c3f2a69a..3de624fa 100644
--- a/java/util/pom.xml
+++ b/java/util/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.5.0</version>
+    <version>3.5.1</version>
   </parent>
 
   <artifactId>protobuf-java-util</artifactId>
diff --git a/js/package.json b/js/package.json
index 50ebdac8..3c1c2a42 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "google-protobuf",
-  "version": "3.5.0",
+  "version": "3.5.1",
   "description": "Protocol Buffers for JavaScript",
   "main": "google-protobuf.js",
   "files": [
diff --git a/php/ext/google/protobuf/def.c b/php/ext/google/protobuf/def.c
index 13f7cdd6..8140fe47 100644
--- a/php/ext/google/protobuf/def.c
+++ b/php/ext/google/protobuf/def.c
@@ -249,9 +249,11 @@ PHP_METHOD(Descriptor, getField) {
     MAKE_STD_ZVAL(field_hashtable_value);
     ZVAL_OBJ(field_hashtable_value, field_descriptor_type->create_object(
                                         field_descriptor_type TSRMLS_CC));
+    Z_DELREF_P(field_hashtable_value);
 #else
     field_hashtable_value =
         field_descriptor_type->create_object(field_descriptor_type TSRMLS_CC);
+    --GC_REFCOUNT(field_hashtable_value);
 #endif
     FieldDescriptor *field_php =
         UNBOX_HASHTABLE_VALUE(FieldDescriptor, field_hashtable_value);
diff --git a/php/ext/google/protobuf/encode_decode.c b/php/ext/google/protobuf/encode_decode.c
index ae5a61f5..b98121bb 100644
--- a/php/ext/google/protobuf/encode_decode.c
+++ b/php/ext/google/protobuf/encode_decode.c
@@ -1402,7 +1402,6 @@ static void putarray(zval* array, const upb_fielddef* f, upb_sink* sink,
   RepeatedField* intern = UNBOX(RepeatedField, array);
   HashTable *ht = PHP_PROTO_HASH_OF(intern->array);
   size = zend_hash_num_elements(ht);
-  // size = zend_hash_num_elements(PHP_PROTO_HASH_OF(intern->array));
   if (size == 0) return;
 
   upb_sink_startseq(sink, getsel(f, UPB_HANDLER_STARTSEQ), &subsink);
@@ -1615,11 +1614,101 @@ PHP_METHOD(Message, mergeFromJsonString) {
   }
 }
 
-PHP_METHOD(Message, discardUnknownFields) {
-  MessageHeader* msg = UNBOX(MessageHeader, getThis());
+// TODO(teboring): refactoring with putrawmsg
+static void discard_unknown_fields(MessageHeader* msg) {
+  upb_msg_field_iter it;
+
   stringsink* unknown = DEREF(message_data(msg), 0, stringsink*);
   if (unknown != NULL) {
     stringsink_uninit(unknown);
     DEREF(message_data(msg), 0, stringsink*) = NULL;
   }
+
+  // Recursively discard unknown fields of submessages.
+  Descriptor* desc = msg->descriptor;
+  TSRMLS_FETCH();
+  for (upb_msg_field_begin(&it, desc->msgdef);
+       !upb_msg_field_done(&it);
+       upb_msg_field_next(&it)) {
+    upb_fielddef* f = upb_msg_iter_field(&it);
+    uint32_t offset = desc->layout->fields[upb_fielddef_index(f)].offset;
+    bool containing_oneof = false;
+
+    if (upb_fielddef_containingoneof(f)) {
+      uint32_t oneof_case_offset =
+          desc->layout->fields[upb_fielddef_index(f)].case_offset;
+      // For a oneof, check that this field is actually present -- skip all the
+      // below if not.
+      if (DEREF(message_data(msg), oneof_case_offset, uint32_t) !=
+          upb_fielddef_number(f)) {
+        continue;
+      }
+      // Otherwise, fall through to the appropriate singular-field handler
+      // below.
+      containing_oneof = true;
+    }
+
+    if (is_map_field(f)) {
+      MapIter map_it;
+      int len, size;
+      const upb_fielddef* value_field;
+
+      value_field = map_field_value(f);
+      if (!upb_fielddef_issubmsg(value_field)) continue;
+
+      zval* map_php = CACHED_PTR_TO_ZVAL_PTR(
+          DEREF(message_data(msg), offset, CACHED_VALUE*));
+      if (map_php == NULL) continue;
+
+      Map* intern = UNBOX(Map, map_php);
+      for (map_begin(map_php, &map_it TSRMLS_CC);
+           !map_done(&map_it); map_next(&map_it)) {
+        upb_value value = map_iter_value(&map_it, &len);
+        void* memory = raw_value(upb_value_memory(&value), value_field);
+#if PHP_MAJOR_VERSION < 7
+        MessageHeader *submsg = UNBOX(MessageHeader, *(zval**)memory);
+#else
+        MessageHeader *submsg =
+            (MessageHeader*)((char*)(Z_OBJ_P((zval*)memory)) -
+                XtOffsetOf(MessageHeader, std));
+#endif
+        discard_unknown_fields(submsg);
+      }
+    } else if (upb_fielddef_isseq(f)) {
+      if (!upb_fielddef_issubmsg(f)) continue;
+
+      zval* array_php = CACHED_PTR_TO_ZVAL_PTR(
+          DEREF(message_data(msg), offset, CACHED_VALUE*));
+      if (array_php == NULL) continue;
+
+      int size, i;
+      RepeatedField* intern = UNBOX(RepeatedField, array_php);
+      HashTable *ht = PHP_PROTO_HASH_OF(intern->array);
+      size = zend_hash_num_elements(ht);
+      if (size == 0) continue;
+
+      for (i = 0; i < size; i++) {
+        void* memory = repeated_field_index_native(intern, i TSRMLS_CC);
+#if PHP_MAJOR_VERSION < 7
+        MessageHeader *submsg = UNBOX(MessageHeader, *(zval**)memory);
+#else
+        MessageHeader *submsg =
+            (MessageHeader*)((char*)(Z_OBJ_P((zval*)memory)) -
+                XtOffsetOf(MessageHeader, std));
+#endif
+        discard_unknown_fields(submsg);
+      }
+    } else if (upb_fielddef_issubmsg(f)) {
+      zval* submsg_php = CACHED_PTR_TO_ZVAL_PTR(
+          DEREF(message_data(msg), offset, CACHED_VALUE*));
+      if (Z_TYPE_P(submsg_php) == IS_NULL) continue;
+      MessageHeader* submsg = UNBOX(MessageHeader, submsg_php);
+      discard_unknown_fields(submsg);
+    }
+  }
+}
+
+PHP_METHOD(Message, discardUnknownFields) {
+  MessageHeader* msg = UNBOX(MessageHeader, getThis());
+  discard_unknown_fields(msg);
 }
diff --git a/php/ext/google/protobuf/message.c b/php/ext/google/protobuf/message.c
index 6db010c5..24472682 100644
--- a/php/ext/google/protobuf/message.c
+++ b/php/ext/google/protobuf/message.c
@@ -29,7 +29,6 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <php.h>
-#include <ext/date/php_date.h>
 #include <stdlib.h>
 
 #include "protobuf.h"
@@ -379,6 +378,7 @@ PHP_METHOD(Message, whichOneof) {
     PHP_PROTO_FAKE_SCOPE_BEGIN(LOWER_CLASS##_type);                            \
     zval* value = message_get_property_internal(getThis(), &member TSRMLS_CC); \
     PHP_PROTO_FAKE_SCOPE_END;                                                  \
+    zval_dtor(&member);                                                        \
     PHP_PROTO_RETVAL_ZVAL(value);                                              \
   }                                                                            \
   PHP_METHOD(UPPER_CLASS, set##UPPER_FIELD) {                                  \
@@ -390,6 +390,7 @@ PHP_METHOD(Message, whichOneof) {
     zval member;                                                               \
     PHP_PROTO_ZVAL_STRING(&member, LOWER_FIELD, 1);                            \
     message_set_property_internal(getThis(), &member, value TSRMLS_CC);        \
+    zval_dtor(&member);                                                        \
     PHP_PROTO_RETVAL_ZVAL(getThis());                                          \
   }
 
@@ -402,6 +403,7 @@ PHP_METHOD(Message, whichOneof) {
     message_get_oneof_property_internal(getThis(), &member,                    \
                                         return_value TSRMLS_CC);               \
     PHP_PROTO_FAKE_SCOPE_END;                                                  \
+    zval_dtor(&member);                                                        \
   }                                                                            \
   PHP_METHOD(UPPER_CLASS, set##UPPER_FIELD) {                                  \
     zval* value = NULL;                                                        \
@@ -412,6 +414,7 @@ PHP_METHOD(Message, whichOneof) {
     zval member;                                                               \
     PHP_PROTO_ZVAL_STRING(&member, LOWER_FIELD, 1);                            \
     message_set_property_internal(getThis(), &member, value TSRMLS_CC);        \
+    zval_dtor(&member);                                                        \
     PHP_PROTO_RETVAL_ZVAL(getThis());                                          \
   }
 
@@ -1120,17 +1123,41 @@ PHP_METHOD(Timestamp, fromDateTime) {
   zval* datetime;
   zval member;
 
+  PHP_PROTO_CE_DECLARE date_interface_ce;
+  if (php_proto_zend_lookup_class("\\DatetimeInterface", 18,
+                                  &date_interface_ce) == FAILURE) {
+    zend_error(E_ERROR, "Make sure date extension is enabled.");
+    return;
+  }
+
   if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "O", &datetime,
-                            php_date_get_date_ce()) == FAILURE) {
+                            PHP_PROTO_CE_UNREF(date_interface_ce)) == FAILURE) {
+    zend_error(E_USER_ERROR, "Expect DatetimeInterface.");
     return;
   }
 
-  php_date_obj* dateobj = UNBOX(php_date_obj, datetime);
-  if (!dateobj->time->sse_uptodate) {
-    timelib_update_ts(dateobj->time, NULL);
+  // Get timestamp from Datetime object.
+  zval retval;
+  zval function_name;
+  int64_t timestamp;
+
+#if PHP_MAJOR_VERSION < 7
+  INIT_ZVAL(retval);
+  INIT_ZVAL(function_name);
+#endif
+
+  PHP_PROTO_ZVAL_STRING(&function_name, "date_timestamp_get", 1);
+
+  if (call_user_function(EG(function_table), NULL, &function_name, &retval, 1,
+          ZVAL_PTR_TO_CACHED_PTR(datetime) TSRMLS_CC) == FAILURE) {
+    zend_error(E_ERROR, "Cannot get timestamp from DateTime.");
+    return;
   }
 
-  int64_t timestamp = dateobj->time->sse;
+  protobuf_convert_to_int64(&retval, &timestamp);
+
+  zval_dtor(&retval);
+  zval_dtor(&function_name);
 
   // Set seconds
   MessageHeader* self = UNBOX(MessageHeader, getThis());
@@ -1138,20 +1165,18 @@ PHP_METHOD(Timestamp, fromDateTime) {
       upb_msgdef_ntofz(self->descriptor->msgdef, "seconds");
   void* storage = message_data(self);
   void* memory = slot_memory(self->descriptor->layout, storage, field);
-  *(int64_t*)memory = dateobj->time->sse;
+  *(int64_t*)memory = timestamp;
 
   // Set nanos
   field = upb_msgdef_ntofz(self->descriptor->msgdef, "nanos");
   storage = message_data(self);
   memory = slot_memory(self->descriptor->layout, storage, field);
   *(int32_t*)memory = 0;
+
+  RETURN_NULL();
 }
 
 PHP_METHOD(Timestamp, toDateTime) {
-  zval datetime;
-  php_date_instantiate(php_date_get_date_ce(), &datetime TSRMLS_CC);
-  php_date_obj* dateobj = UNBOX(php_date_obj, &datetime);
-
   // Get seconds
   MessageHeader* self = UNBOX(MessageHeader, getThis());
   const upb_fielddef* field =
@@ -1172,14 +1197,38 @@ PHP_METHOD(Timestamp, toDateTime) {
   strftime(formated_time, sizeof(formated_time), "%Y-%m-%dT%H:%M:%SUTC",
            utc_time);
 
-  if (!php_date_initialize(dateobj, formated_time, strlen(formated_time), NULL,
-                           NULL, 0 TSRMLS_CC)) {
-    zval_dtor(&datetime);
-    RETURN_NULL();
+  // Create Datetime object.
+  zval datetime;
+  zval formated_time_php;
+  zval function_name;
+  int64_t timestamp = 0;
+
+#if PHP_MAJOR_VERSION < 7
+  INIT_ZVAL(function_name);
+  INIT_ZVAL(formated_time_php);
+#endif
+
+  PHP_PROTO_ZVAL_STRING(&function_name, "date_create", 1);
+  PHP_PROTO_ZVAL_STRING(&formated_time_php, formated_time, 1);
+
+  CACHED_VALUE params[1] = {ZVAL_TO_CACHED_VALUE(formated_time_php)};
+
+  if (call_user_function(EG(function_table), NULL,
+                         &function_name, &datetime, 1,
+                         params TSRMLS_CC) == FAILURE) {
+    zend_error(E_ERROR, "Cannot create DateTime.");
+    return;
   }
 
+  zval_dtor(&formated_time_php);
+  zval_dtor(&function_name);
+
+#if PHP_MAJOR_VERSION < 7
   zval* datetime_ptr = &datetime;
   PHP_PROTO_RETVAL_ZVAL(datetime_ptr);
+#else
+  ZVAL_OBJ(return_value, Z_OBJ(datetime));
+#endif
 }
 
 // -----------------------------------------------------------------------------
diff --git a/php/ext/google/protobuf/package.xml b/php/ext/google/protobuf/package.xml
index 53aa4c7f..626eb46b 100644
--- a/php/ext/google/protobuf/package.xml
+++ b/php/ext/google/protobuf/package.xml
@@ -10,11 +10,11 @@
   <email>protobuf-opensource@google.com</email>
   <active>yes</active>
  </lead>
- <date>2017-11-15</date>
+ <date>2017-12-11</date>
  <time>11:02:07</time>
  <version>
-  <release>3.5.0</release>
-  <api>3.5.0</api>
+  <release>3.5.1</release>
+  <api>3.5.1</api>
  </version>
  <stability>
   <release>stable</release>
@@ -184,5 +184,37 @@ GA release.
 GA release.
    </notes>
   </release>
+  <release>
+   <version>
+    <release>3.5.0.1</release>
+    <api>3.5.0.1</api>
+   </version>
+   <stability>
+    <release>stable</release>
+    <api>stable</api>
+   </stability>
+   <date>2017-12-06</date>
+   <time>11:02:07</time>
+   <license uri="https://opensource.org/licenses/BSD-3-Clause">3-Clause BSD License</license>
+   <notes>
+GA release.
+   </notes>
+  </release>
+  <release>
+   <version>
+    <release>3.5.1</release>
+    <api>3.5.1</api>
+   </version>
+   <stability>
+    <release>stable</release>
+    <api>stable</api>
+   </stability>
+   <date>2017-12-11</date>
+   <time>11:02:07</time>
+   <license uri="https://opensource.org/licenses/BSD-3-Clause">3-Clause BSD License</license>
+   <notes>
+GA release.
+   </notes>
+  </release>
  </changelog>
 </package>
diff --git a/php/ext/google/protobuf/protobuf.c b/php/ext/google/protobuf/protobuf.c
index 265d636e..daebb460 100644
--- a/php/ext/google/protobuf/protobuf.c
+++ b/php/ext/google/protobuf/protobuf.c
@@ -182,8 +182,15 @@ zend_function_entry protobuf_functions[] = {
   ZEND_FE_END
 };
 
+static const zend_module_dep protobuf_deps[] = {
+  ZEND_MOD_OPTIONAL("date")
+  ZEND_MOD_END
+};
+
 zend_module_entry protobuf_module_entry = {
-  STANDARD_MODULE_HEADER,
+  STANDARD_MODULE_HEADER_EX,
+  NULL,
+  protobuf_deps,
   PHP_PROTOBUF_EXTNAME,     // extension name
   protobuf_functions,       // function list
   PHP_MINIT(protobuf),      // process startup
diff --git a/php/ext/google/protobuf/protobuf.h b/php/ext/google/protobuf/protobuf.h
index bd475144..6ab0f134 100644
--- a/php/ext/google/protobuf/protobuf.h
+++ b/php/ext/google/protobuf/protobuf.h
@@ -37,7 +37,7 @@
 #include "upb.h"
 
 #define PHP_PROTOBUF_EXTNAME "protobuf"
-#define PHP_PROTOBUF_VERSION "3.5.0"
+#define PHP_PROTOBUF_VERSION "3.5.1"
 
 #define MAX_LENGTH_OF_INT64 20
 #define SIZEOF_INT64 8
@@ -182,6 +182,8 @@
 #define CACHED_TO_ZVAL_PTR(VALUE) (VALUE)
 #define CACHED_PTR_TO_ZVAL_PTR(VALUE) (*VALUE)
 #define ZVAL_PTR_TO_CACHED_PTR(VALUE) (&VALUE)
+#define ZVAL_PTR_TO_CACHED_VALUE(VALUE) (VALUE)
+#define ZVAL_TO_CACHED_VALUE(VALUE) (&VALUE)
 
 #define CREATE_OBJ_ON_ALLOCATED_ZVAL_PTR(zval_ptr, class_type) \
   ZVAL_OBJ(zval_ptr, class_type->create_object(class_type TSRMLS_CC));
@@ -452,6 +454,8 @@ static inline int php_proto_zend_hash_get_current_data_ex(HashTable* ht,
 #define CACHED_TO_ZVAL_PTR(VALUE) (&VALUE)
 #define CACHED_PTR_TO_ZVAL_PTR(VALUE) (VALUE)
 #define ZVAL_PTR_TO_CACHED_PTR(VALUE) (VALUE)
+#define ZVAL_PTR_TO_CACHED_VALUE(VALUE) (*VALUE)
+#define ZVAL_TO_CACHED_VALUE(VALUE) (VALUE)
 
 #define CREATE_OBJ_ON_ALLOCATED_ZVAL_PTR(zval_ptr, class_type) \
   ZVAL_OBJ(zval_ptr, class_type->create_object(class_type));
diff --git a/php/ext/google/protobuf/type_check.c b/php/ext/google/protobuf/type_check.c
index f588774c..85f5051e 100644
--- a/php/ext/google/protobuf/type_check.c
+++ b/php/ext/google/protobuf/type_check.c
@@ -461,8 +461,7 @@ void check_repeated_field(const zend_class_entry* klass, PHP_PROTO_LONG type,
           CACHED_PTR_TO_ZVAL_PTR((CACHED_VALUE*)memory) TSRMLS_CC);
     }
 
-    Z_DELREF_P(CACHED_TO_ZVAL_PTR(repeated_field));
-    RETURN_ZVAL(CACHED_TO_ZVAL_PTR(repeated_field), 1, 0);
+    RETURN_ZVAL(CACHED_TO_ZVAL_PTR(repeated_field), 1, 1);
 
   } else if (Z_TYPE_P(val) == IS_OBJECT) {
     if (!instanceof_function(Z_OBJCE_P(val), repeated_field_type TSRMLS_CC)) {
@@ -533,10 +532,10 @@ void check_map_field(const zend_class_entry* klass, PHP_PROTO_LONG key_type,
       map_field_handlers->write_dimension(
           CACHED_TO_ZVAL_PTR(map_field), &key,
           CACHED_PTR_TO_ZVAL_PTR((CACHED_VALUE*)value) TSRMLS_CC);
+      zval_dtor(&key);
     }
 
-    Z_DELREF_P(CACHED_TO_ZVAL_PTR(map_field));
-    RETURN_ZVAL(CACHED_TO_ZVAL_PTR(map_field), 1, 0);
+    RETURN_ZVAL(CACHED_TO_ZVAL_PTR(map_field), 1, 1);
   } else if (Z_TYPE_P(val) == IS_OBJECT) {
     if (!instanceof_function(Z_OBJCE_P(val), map_field_type TSRMLS_CC)) {
       zend_error(E_USER_ERROR, "Given value is not an instance of %s.",
diff --git a/php/src/Google/Protobuf/Internal/Message.php b/php/src/Google/Protobuf/Internal/Message.php
index 26d20575..b7f83c57 100644
--- a/php/src/Google/Protobuf/Internal/Message.php
+++ b/php/src/Google/Protobuf/Internal/Message.php
@@ -583,6 +583,34 @@ class Message
     public function discardUnknownFields()
     {
         $this->unknown = "";
+        foreach ($this->desc->getField() as $field) {
+            if ($field->getType() != GPBType::MESSAGE) {
+                continue;
+            }
+            if ($field->isMap()) {
+                $value_field = $field->getMessageType()->getFieldByNumber(2);
+                if ($value_field->getType() != GPBType::MESSAGE) {
+                    continue;
+                }
+                $getter = $field->getGetter();
+                $map = $this->$getter();
+                foreach ($map as $key => $value) {
+                    $value->discardUnknownFields();
+                }
+            } else if ($field->getLabel() === GPBLabel::REPEATED) {
+                $getter = $field->getGetter();
+                $arr = $this->$getter();
+                foreach ($arr as $sub) {
+                    $sub->discardUnknownFields();
+                }
+            } else if ($field->getLabel() === GPBLabel::OPTIONAL) {
+                $getter = $field->getGetter();
+                $sub = $this->$getter();
+                if (!is_null($sub)) {
+                    $sub->discardUnknownFields();
+                }
+            }
+        }
     }
 
     /**
@@ -1083,7 +1111,7 @@ class Message
         }
         try {
             $this->mergeFromJsonArray($array);
-        } catch (Exception $e) {
+        } catch (\Exception $e) {
             throw new GPBDecodeException($e->getMessage());
         }
     }
diff --git a/php/tests/encode_decode_test.php b/php/tests/encode_decode_test.php
index 4512c871..74d5526d 100644
--- a/php/tests/encode_decode_test.php
+++ b/php/tests/encode_decode_test.php
@@ -443,36 +443,74 @@ class EncodeDecodeTest extends TestBase
 
     public function testUnknown()
     {
+        // Test preserve unknown for varint.
         $m = new TestMessage();
-        $from = hex2bin('F80601');
+        $from = hex2bin('F80601');  // TODO(teboring): Add a util to encode
+                                    // varint for better readability
         $m->mergeFromString($from);
         $to = $m->serializeToString();
         $this->assertSame(bin2hex($from), bin2hex($to));
 
+        // Test preserve unknown for 64-bit.
         $m = new TestMessage();
         $from = hex2bin('F9060000000000000000');
         $m->mergeFromString($from);
         $to = $m->serializeToString();
         $this->assertSame(bin2hex($from), bin2hex($to));
 
+        // Test preserve unknown for length delimited.
         $m = new TestMessage();
         $from = hex2bin('FA0600');
         $m->mergeFromString($from);
         $to = $m->serializeToString();
         $this->assertSame(bin2hex($from), bin2hex($to));
 
+        // Test preserve unknown for 32-bit.
         $m = new TestMessage();
         $from = hex2bin('FD0600000000');
         $m->mergeFromString($from);
         $to = $m->serializeToString();
         $this->assertSame(bin2hex($from), bin2hex($to));
 
+        // Test discard unknown in message.
         $m = new TestMessage();
         $from = hex2bin('F80601');
         $m->mergeFromString($from);
         $m->discardUnknownFields();
         $to = $m->serializeToString();
         $this->assertSame("", bin2hex($to));
+
+        // Test discard unknown for singular message field.
+        $m = new TestMessage();
+        $from = hex2bin('8A0103F80601');
+        $m->mergeFromString($from);
+        $m->discardUnknownFields();
+        $to = $m->serializeToString();
+        $this->assertSame("8a0100", bin2hex($to));
+
+        // Test discard unknown for repeated message field.
+        $m = new TestMessage();
+        $from = hex2bin('FA0203F80601');
+        $m->mergeFromString($from);
+        $m->discardUnknownFields();
+        $to = $m->serializeToString();
+        $this->assertSame("fa0200", bin2hex($to));
+
+        // Test discard unknown for map message value field.
+        $m = new TestMessage();
+        $from = hex2bin("BA050708011203F80601");
+        $m->mergeFromString($from);
+        $m->discardUnknownFields();
+        $to = $m->serializeToString();
+        $this->assertSame("ba050408011200", bin2hex($to));
+
+        // Test discard unknown for singular message field.
+        $m = new TestMessage();
+        $from = hex2bin('9A0403F80601');
+        $m->mergeFromString($from);
+        $m->discardUnknownFields();
+        $to = $m->serializeToString();
+        $this->assertSame("9a0400", bin2hex($to));
     }
 
     public function testJsonEncode()
diff --git a/php/tests/memory_leak_test.php b/php/tests/memory_leak_test.php
index b76c8bff..507635e7 100644
--- a/php/tests/memory_leak_test.php
+++ b/php/tests/memory_leak_test.php
@@ -50,7 +50,8 @@ $to->mergeFromString($data);
 
 TestUtil::assertTestMessage($to);
 
-$from->setRecursive($from);
+// TODO(teboring): This causes following tests fail in php7.
+# $from->setRecursive($from);
 
 $arr = new RepeatedField(GPBType::MESSAGE, TestMessage::class);
 $arr[] = new TestMessage;
@@ -105,6 +106,47 @@ $m = new TestMessage();
 $m->mergeFromString(hex2bin('F80601'));
 assert('F80601', bin2hex($m->serializeToString()));
 
+// Test create repeated field via array.
+$str_arr = array("abc");
+$m = new TestMessage();
+$m->setRepeatedString($str_arr);
+
+// Test create map field via array.
+$str_arr = array("abc"=>"abc");
+$m = new TestMessage();
+$m->setMapStringString($str_arr);
+
+// Test unset
+$from = new TestMessage();
+TestUtil::setTestMessage($from);
+unset($from);
+
+// Test wellknown
+$from = new \Google\Protobuf\Timestamp();
+$from->setSeconds(1);
+assert(1, $from->getSeconds());
+
+$timestamp = new \Google\Protobuf\Timestamp();
+
+date_default_timezone_set('UTC');
+$from = new DateTime('2011-01-01T15:03:01.012345UTC');
+$timestamp->fromDateTime($from);
+assert($from->format('U') == $timestamp->getSeconds());
+assert(0 == $timestamp->getNanos());
+
+$to = $timestamp->toDateTime();
+assert(\DateTime::class == get_class($to));
+assert($from->format('U') == $to->format('U'));
+
+$from = new \Google\Protobuf\Value();
+$from->setNumberValue(1);
+assert(1, $from->getNumberValue());
+
+// Test descriptor
+$pool = \Google\Protobuf\DescriptorPool::getGeneratedPool();
+$desc = $pool->getDescriptorByClassName("\Foo\TestMessage");
+$field = $desc->getField(1);
+
 # $from = new TestMessage();
 # $to = new TestMessage();
 # TestUtil::setTestMessage($from);
diff --git a/protoc-artifacts/pom.xml b/protoc-artifacts/pom.xml
index 742fab93..0f9dd9f8 100644
--- a/protoc-artifacts/pom.xml
+++ b/protoc-artifacts/pom.xml
@@ -10,7 +10,7 @@
   </parent>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protoc</artifactId>
-  <version>3.5.0</version>
+  <version>3.5.1</version>
   <packaging>pom</packaging>
   <name>Protobuf Compiler</name>
   <description>
diff --git a/python/google/protobuf/__init__.py b/python/google/protobuf/__init__.py
index 0f4d63b0..950f9b2d 100755
--- a/python/google/protobuf/__init__.py
+++ b/python/google/protobuf/__init__.py
@@ -30,7 +30,7 @@
 
 # Copyright 2007 Google Inc. All Rights Reserved.
 
-__version__ = '3.5.0.post1'
+__version__ = '3.5.1'
 
 if __name__ != '__main__':
   try:
diff --git a/python/release.sh b/python/release.sh
index 01fc5e23..a71cc7f5 100755
--- a/python/release.sh
+++ b/python/release.sh
@@ -19,7 +19,7 @@ function run_install_test() {
   chmod +x test-venv/bin/protoc
 
   source test-venv/bin/activate
-  pip install -i ${PYPI} protobuf==${VERSION}
+  pip install -i ${PYPI} protobuf==${VERSION} --no-cache-dir
   deactivate
   rm -fr test-venv
 }
@@ -88,6 +88,7 @@ run_install_test ${TESTING_VERSION} python3.4 https://test.pypi.org/simple
 
 # Deploy egg/wheel packages to testing PyPI and test again.
 python setup.py bdist_egg bdist_wheel upload -r https://test.pypi.org/legacy/
+
 run_install_test ${TESTING_VERSION} python2.7 https://test.pypi.org/simple
 run_install_test ${TESTING_VERSION} python3.4 https://test.pypi.org/simple
 
diff --git a/python/release/wheel/protobuf_optimized_pip.sh b/python/release/wheel/protobuf_optimized_pip.sh
index 064d1d2a..98306f4c 100755
--- a/python/release/wheel/protobuf_optimized_pip.sh
+++ b/python/release/wheel/protobuf_optimized_pip.sh
@@ -6,7 +6,7 @@ set -ex
 
 # Print usage and fail.
 function usage() {
-  echo "Usage: protobuf_optimized_pip.sh PROTOBUF_VERSION PYPI_USERNAME PYPI_PASSWORD" >&2
+  echo "Usage: protobuf_optimized_pip.sh PROTOBUF_VERSION" >&2
   exit 1   # Causes caller to exit because we use -e.
 }
 
@@ -25,7 +25,7 @@ if [ $0 != ./protobuf_optimized_pip.sh ]; then
   exit 1
 fi
 
-if [ $# -lt 3 ]; then
+if [ $# -lt 1 ]; then
   usage
   exit 1
 fi
@@ -63,7 +63,4 @@ do
   build_wheel $PYTHON_VERSION
 done
 
-/opt/python/cp27-cp27mu/bin/twine upload wheelhouse/* <<!
-$PYPI_USERNAME
-$PYPI_PASSWORD
-!
+/opt/python/cp27-cp27mu/bin/twine upload wheelhouse/*
diff --git a/python/setup.py b/python/setup.py
index efb74fe7..0f7e58b0 100755
--- a/python/setup.py
+++ b/python/setup.py
@@ -240,7 +240,6 @@ if __name__ == '__main__':
       classifiers=[
         "Programming Language :: Python",
         "Programming Language :: Python :: 2",
-        "Programming Language :: Python :: 2.6",
         "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3",
         "Programming Language :: Python :: 3.3",
diff --git a/ruby/ext/google/protobuf_c/defs.c b/ruby/ext/google/protobuf_c/defs.c
index 34d9663a..d9d2ebac 100644
--- a/ruby/ext/google/protobuf_c/defs.c
+++ b/ruby/ext/google/protobuf_c/defs.c
@@ -76,7 +76,7 @@ static upb_enumdef* check_enum_notfrozen(const upb_enumdef* def) {
 // -----------------------------------------------------------------------------
 
 #define DEFINE_CLASS(name, string_name)                             \
-    VALUE c ## name;                                                \
+    VALUE c ## name = Qnil;                                         \
     const rb_data_type_t _ ## name ## _type = {                     \
       string_name,                                                  \
       { name ## _mark, name ## _free, NULL },                       \
@@ -126,11 +126,11 @@ void DescriptorPool_register(VALUE module) {
   rb_define_method(klass, "lookup", DescriptorPool_lookup, 1);
   rb_define_singleton_method(klass, "generated_pool",
                              DescriptorPool_generated_pool, 0);
-  cDescriptorPool = klass;
   rb_gc_register_address(&cDescriptorPool);
+  cDescriptorPool = klass;
 
-  generated_pool = rb_class_new_instance(0, NULL, klass);
   rb_gc_register_address(&generated_pool);
+  generated_pool = rb_class_new_instance(0, NULL, klass);
 }
 
 static void add_descriptor_to_pool(DescriptorPool* self,
@@ -299,8 +299,8 @@ void Descriptor_register(VALUE module) {
   rb_define_method(klass, "name", Descriptor_name, 0);
   rb_define_method(klass, "name=", Descriptor_name_set, 1);
   rb_include_module(klass, rb_mEnumerable);
-  cDescriptor = klass;
   rb_gc_register_address(&cDescriptor);
+  cDescriptor = klass;
 }
 
 /*
@@ -518,8 +518,8 @@ void FieldDescriptor_register(VALUE module) {
   rb_define_method(klass, "subtype", FieldDescriptor_subtype, 0);
   rb_define_method(klass, "get", FieldDescriptor_get, 1);
   rb_define_method(klass, "set", FieldDescriptor_set, 2);
-  cFieldDescriptor = klass;
   rb_gc_register_address(&cFieldDescriptor);
+  cFieldDescriptor = klass;
 }
 
 /*
@@ -916,8 +916,8 @@ void OneofDescriptor_register(VALUE module) {
   rb_define_method(klass, "add_field", OneofDescriptor_add_field, 1);
   rb_define_method(klass, "each", OneofDescriptor_each, 0);
   rb_include_module(klass, rb_mEnumerable);
-  cOneofDescriptor = klass;
   rb_gc_register_address(&cOneofDescriptor);
+  cOneofDescriptor = klass;
 }
 
 /*
@@ -1037,8 +1037,8 @@ void EnumDescriptor_register(VALUE module) {
   rb_define_method(klass, "each", EnumDescriptor_each, 0);
   rb_define_method(klass, "enummodule", EnumDescriptor_enummodule, 0);
   rb_include_module(klass, rb_mEnumerable);
-  cEnumDescriptor = klass;
   rb_gc_register_address(&cEnumDescriptor);
+  cEnumDescriptor = klass;
 }
 
 /*
@@ -1202,8 +1202,8 @@ void MessageBuilderContext_register(VALUE module) {
   rb_define_method(klass, "repeated", MessageBuilderContext_repeated, -1);
   rb_define_method(klass, "map", MessageBuilderContext_map, -1);
   rb_define_method(klass, "oneof", MessageBuilderContext_oneof, 1);
-  cMessageBuilderContext = klass;
   rb_gc_register_address(&cMessageBuilderContext);
+  cMessageBuilderContext = klass;
 }
 
 /*
@@ -1491,8 +1491,8 @@ void OneofBuilderContext_register(VALUE module) {
   rb_define_method(klass, "initialize",
                    OneofBuilderContext_initialize, 2);
   rb_define_method(klass, "optional", OneofBuilderContext_optional, -1);
-  cOneofBuilderContext = klass;
   rb_gc_register_address(&cOneofBuilderContext);
+  cOneofBuilderContext = klass;
 }
 
 /*
@@ -1569,8 +1569,8 @@ void EnumBuilderContext_register(VALUE module) {
   rb_define_method(klass, "initialize",
                    EnumBuilderContext_initialize, 1);
   rb_define_method(klass, "value", EnumBuilderContext_value, 2);
-  cEnumBuilderContext = klass;
   rb_gc_register_address(&cEnumBuilderContext);
+  cEnumBuilderContext = klass;
 }
 
 /*
@@ -1645,8 +1645,8 @@ void Builder_register(VALUE module) {
   rb_define_method(klass, "add_enum", Builder_add_enum, 1);
   rb_define_method(klass, "initialize", Builder_initialize, 0);
   rb_define_method(klass, "finalize_to_pool", Builder_finalize_to_pool, 1);
-  cBuilder = klass;
   rb_gc_register_address(&cBuilder);
+  cBuilder = klass;
 }
 
 /*
diff --git a/ruby/ext/google/protobuf_c/encode_decode.c b/ruby/ext/google/protobuf_c/encode_decode.c
index d1b6e89e..12080d03 100644
--- a/ruby/ext/google/protobuf_c/encode_decode.c
+++ b/ruby/ext/google/protobuf_c/encode_decode.c
@@ -1305,3 +1305,91 @@ VALUE Message_encode_json(int argc, VALUE* argv, VALUE klass) {
   }
 }
 
+static void discard_unknown(VALUE msg_rb, const Descriptor* desc) {
+  MessageHeader* msg;
+  upb_msg_field_iter it;
+
+  TypedData_Get_Struct(msg_rb, MessageHeader, &Message_type, msg);
+
+  stringsink* unknown = msg->unknown_fields;
+  if (unknown != NULL) {
+    stringsink_uninit(unknown);
+    msg->unknown_fields = NULL;
+  }
+
+  for (upb_msg_field_begin(&it, desc->msgdef);
+       !upb_msg_field_done(&it);
+       upb_msg_field_next(&it)) {
+    upb_fielddef *f = upb_msg_iter_field(&it);
+    uint32_t offset =
+        desc->layout->fields[upb_fielddef_index(f)].offset +
+        sizeof(MessageHeader);
+
+    if (upb_fielddef_containingoneof(f)) {
+      uint32_t oneof_case_offset =
+          desc->layout->fields[upb_fielddef_index(f)].case_offset +
+          sizeof(MessageHeader);
+      // For a oneof, check that this field is actually present -- skip all the
+      // below if not.
+      if (DEREF(msg, oneof_case_offset, uint32_t) !=
+          upb_fielddef_number(f)) {
+        continue;
+      }
+      // Otherwise, fall through to the appropriate singular-field handler
+      // below.
+    }
+
+    if (!upb_fielddef_issubmsg(f)) {
+      continue;
+    }
+
+    if (is_map_field(f)) {
+      if (!upb_fielddef_issubmsg(map_field_value(f))) continue;
+      VALUE map = DEREF(msg, offset, VALUE);
+      if (map == Qnil) continue;
+      Map_iter map_it;
+      for (Map_begin(map, &map_it); !Map_done(&map_it); Map_next(&map_it)) {
+        VALUE submsg = Map_iter_value(&map_it);
+        VALUE descriptor = rb_ivar_get(submsg, descriptor_instancevar_interned);
+        const Descriptor* subdesc = ruby_to_Descriptor(descriptor);
+        discard_unknown(submsg, subdesc);
+      }
+    } else if (upb_fielddef_isseq(f)) {
+      VALUE ary = DEREF(msg, offset, VALUE);
+      if (ary == Qnil) continue;
+      int size = NUM2INT(RepeatedField_length(ary));
+      for (int i = 0; i < size; i++) {
+        void* memory = RepeatedField_index_native(ary, i);
+        VALUE submsg = *((VALUE *)memory);
+        VALUE descriptor = rb_ivar_get(submsg, descriptor_instancevar_interned);
+        const Descriptor* subdesc = ruby_to_Descriptor(descriptor);
+        discard_unknown(submsg, subdesc);
+      }
+    } else {
+      VALUE submsg = DEREF(msg, offset, VALUE);
+      if (submsg == Qnil) continue;
+      VALUE descriptor = rb_ivar_get(submsg, descriptor_instancevar_interned);
+      const Descriptor* subdesc = ruby_to_Descriptor(descriptor);
+      discard_unknown(submsg, subdesc);
+    }
+  }
+}
+
+/*
+ * call-seq:
+ *     Google::Protobuf.discard_unknown(msg)
+ *
+ * Discard unknown fields in the given message object and recursively discard
+ * unknown fields in submessages.
+ */
+VALUE Google_Protobuf_discard_unknown(VALUE self, VALUE msg_rb) {
+  VALUE klass = CLASS_OF(msg_rb);
+  VALUE descriptor = rb_ivar_get(klass, descriptor_instancevar_interned);
+  Descriptor* desc = ruby_to_Descriptor(descriptor);
+  if (klass == cRepeatedField || klass == cMap) {
+    rb_raise(rb_eArgError, "Expected proto msg for discard unknown.");
+  } else {
+    discard_unknown(msg_rb, desc);
+  }
+  return Qnil;
+}
diff --git a/ruby/ext/google/protobuf_c/map.c b/ruby/ext/google/protobuf_c/map.c
index 26e22dc7..8c2f6424 100644
--- a/ruby/ext/google/protobuf_c/map.c
+++ b/ruby/ext/google/protobuf_c/map.c
@@ -825,8 +825,8 @@ VALUE Map_iter_value(Map_iter* iter) {
 void Map_register(VALUE module) {
   VALUE klass = rb_define_class_under(module, "Map", rb_cObject);
   rb_define_alloc_func(klass, Map_alloc);
-  cMap = klass;
   rb_gc_register_address(&cMap);
+  cMap = klass;
 
   rb_define_method(klass, "initialize", Map_init, -1);
   rb_define_method(klass, "each", Map_each, 0);
diff --git a/ruby/ext/google/protobuf_c/protobuf.c b/ruby/ext/google/protobuf_c/protobuf.c
index c7750c44..db696426 100644
--- a/ruby/ext/google/protobuf_c/protobuf.c
+++ b/ruby/ext/google/protobuf_c/protobuf.c
@@ -103,6 +103,8 @@ void Init_protobuf_c() {
   cError = rb_const_get(protobuf, rb_intern("Error"));
   cParseError = rb_const_get(protobuf, rb_intern("ParseError"));
 
+  rb_define_singleton_method(protobuf, "discard_unknown",
+                             Google_Protobuf_discard_unknown, 1);
   rb_define_singleton_method(protobuf, "deep_copy",
                              Google_Protobuf_deep_copy, 1);
 
diff --git a/ruby/ext/google/protobuf_c/protobuf.h b/ruby/ext/google/protobuf_c/protobuf.h
index 1291ac59..5266aa8d 100644
--- a/ruby/ext/google/protobuf_c/protobuf.h
+++ b/ruby/ext/google/protobuf_c/protobuf.h
@@ -515,6 +515,7 @@ VALUE Message_encode(VALUE klass, VALUE msg_rb);
 VALUE Message_decode_json(VALUE klass, VALUE data);
 VALUE Message_encode_json(int argc, VALUE* argv, VALUE klass);
 
+VALUE Google_Protobuf_discard_unknown(VALUE self, VALUE msg_rb);
 VALUE Google_Protobuf_deep_copy(VALUE self, VALUE obj);
 
 VALUE build_module_from_enumdesc(EnumDescriptor* enumdef);
diff --git a/ruby/ext/google/protobuf_c/repeated_field.c b/ruby/ext/google/protobuf_c/repeated_field.c
index 1c651c19..c6620ee6 100644
--- a/ruby/ext/google/protobuf_c/repeated_field.c
+++ b/ruby/ext/google/protobuf_c/repeated_field.c
@@ -626,8 +626,8 @@ void RepeatedField_register(VALUE module) {
   VALUE klass = rb_define_class_under(
       module, "RepeatedField", rb_cObject);
   rb_define_alloc_func(klass, RepeatedField_alloc);
-  cRepeatedField = klass;
   rb_gc_register_address(&cRepeatedField);
+  cRepeatedField = klass;
 
   rb_define_method(klass, "initialize",
                    RepeatedField_init, -1);
diff --git a/ruby/google-protobuf.gemspec b/ruby/google-protobuf.gemspec
index c3963822..998952d0 100644
--- a/ruby/google-protobuf.gemspec
+++ b/ruby/google-protobuf.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name        = "google-protobuf"
-  s.version     = "3.5.0"
+  s.version     = "3.5.1"
   s.licenses    = ["BSD-3-Clause"]
   s.summary     = "Protocol Buffers"
   s.description = "Protocol Buffers are Google's data interchange format."
diff --git a/ruby/tests/encode_decode_test.rb b/ruby/tests/encode_decode_test.rb
new file mode 100644
index 00000000..09581ab0
--- /dev/null
+++ b/ruby/tests/encode_decode_test.rb
@@ -0,0 +1,63 @@
+#!/usr/bin/ruby
+
+# generated_code.rb is in the same directory as this test.
+$LOAD_PATH.unshift(File.expand_path(File.dirname(__FILE__)))
+
+require 'generated_code_pb'
+require 'test/unit'
+
+def hex2bin(s)
+  s.scan(/../).map { |x| x.hex.chr }.join
+end
+
+class EncodeDecodeTest < Test::Unit::TestCase
+  def test_discard_unknown
+    # Test discard unknown in message.
+    unknown_msg = A::B::C::TestUnknown.new(:unknown_field => 1)
+    from = A::B::C::TestUnknown.encode(unknown_msg)
+    m = A::B::C::TestMessage.decode(from)
+    Google::Protobuf.discard_unknown(m)
+    to = A::B::C::TestMessage.encode(m)
+    assert_equal '', to
+
+    # Test discard unknown for singular message field.
+    unknown_msg = A::B::C::TestUnknown.new(
+	    :optional_unknown =>
+	    A::B::C::TestUnknown.new(:unknown_field => 1))
+    from = A::B::C::TestUnknown.encode(unknown_msg)
+    m = A::B::C::TestMessage.decode(from)
+    Google::Protobuf.discard_unknown(m)
+    to = A::B::C::TestMessage.encode(m.optional_msg)
+    assert_equal '', to
+
+    # Test discard unknown for repeated message field.
+    unknown_msg = A::B::C::TestUnknown.new(
+	    :repeated_unknown =>
+	    [A::B::C::TestUnknown.new(:unknown_field => 1)])
+    from = A::B::C::TestUnknown.encode(unknown_msg)
+    m = A::B::C::TestMessage.decode(from)
+    Google::Protobuf.discard_unknown(m)
+    to = A::B::C::TestMessage.encode(m.repeated_msg[0])
+    assert_equal '', to
+
+    # Test discard unknown for map value message field.
+    unknown_msg = A::B::C::TestUnknown.new(
+	    :map_unknown =>
+	    {"" => A::B::C::TestUnknown.new(:unknown_field => 1)})
+    from = A::B::C::TestUnknown.encode(unknown_msg)
+    m = A::B::C::TestMessage.decode(from)
+    Google::Protobuf.discard_unknown(m)
+    to = A::B::C::TestMessage.encode(m.map_string_msg[''])
+    assert_equal '', to
+
+    # Test discard unknown for oneof message field.
+    unknown_msg = A::B::C::TestUnknown.new(
+	    :oneof_unknown =>
+	    A::B::C::TestUnknown.new(:unknown_field => 1))
+    from = A::B::C::TestUnknown.encode(unknown_msg)
+    m = A::B::C::TestMessage.decode(from)
+    Google::Protobuf.discard_unknown(m)
+    to = A::B::C::TestMessage.encode(m.oneof_msg)
+    assert_equal '', to
+  end
+end
diff --git a/ruby/tests/generated_code.proto b/ruby/tests/generated_code.proto
index 62fd83ed..3b934bd6 100644
--- a/ruby/tests/generated_code.proto
+++ b/ruby/tests/generated_code.proto
@@ -57,6 +57,9 @@ message TestMessage {
   }
 
   NestedMessage nested_message = 80;
+
+  // Reserved for non-existing field test.
+  // int32 non_exist = 89;
 }
 
 enum TestEnum {
@@ -65,3 +68,13 @@ enum TestEnum {
   B = 2;
   C = 3;
 }
+
+message TestUnknown {
+  TestUnknown optional_unknown = 11;
+  repeated TestUnknown repeated_unknown = 31;
+  oneof my_oneof {
+    TestUnknown oneof_unknown = 51;
+  }
+  map<string, TestUnknown> map_unknown = 67;
+  int32 unknown_field = 89;
+}
diff --git a/src/Makefile.am b/src/Makefile.am
index 9bf254cd..aa945d3e 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -183,7 +183,7 @@ nobase_include_HEADERS =                                         \
 lib_LTLIBRARIES = libprotobuf-lite.la libprotobuf.la libprotoc.la
 
 libprotobuf_lite_la_LIBADD = $(PTHREAD_LIBS)
-libprotobuf_lite_la_LDFLAGS = -version-info 15:0:0 -export-dynamic -no-undefined
+libprotobuf_lite_la_LDFLAGS = -version-info 15:1:0 -export-dynamic -no-undefined
 if HAVE_LD_VERSION_SCRIPT
 libprotobuf_lite_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libprotobuf-lite.map
 EXTRA_libprotobuf_lite_la_DEPENDENCIES = libprotobuf-lite.map
@@ -233,7 +233,7 @@ libprotobuf_lite_la_SOURCES =                                  \
   google/protobuf/io/zero_copy_stream_impl_lite.cc
 
 libprotobuf_la_LIBADD = $(PTHREAD_LIBS)
-libprotobuf_la_LDFLAGS = -version-info 15:0:0 -export-dynamic -no-undefined
+libprotobuf_la_LDFLAGS = -version-info 15:1:0 -export-dynamic -no-undefined
 if HAVE_LD_VERSION_SCRIPT
 libprotobuf_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libprotobuf.map
 EXTRA_libprotobuf_la_DEPENDENCIES = libprotobuf.map
@@ -324,7 +324,7 @@ libprotobuf_la_SOURCES =                                       \
 nodist_libprotobuf_la_SOURCES = $(nodist_libprotobuf_lite_la_SOURCES)
 
 libprotoc_la_LIBADD = $(PTHREAD_LIBS) libprotobuf.la
-libprotoc_la_LDFLAGS = -version-info 15:0:0 -export-dynamic -no-undefined
+libprotoc_la_LDFLAGS = -version-info 15:1:0 -export-dynamic -no-undefined
 if HAVE_LD_VERSION_SCRIPT
 libprotoc_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libprotoc.map
 EXTRA_libprotoc_la_DEPENDENCIES = libprotoc.map
@@ -527,6 +527,7 @@ js_well_known_types_sources =                                  \
 	google/protobuf/compiler/js/well_known_types/timestamp.js
 # We have to cd to $(srcdir) so that out-of-tree builds work properly.
 google/protobuf/compiler/js/well_known_types_embed.cc: js_embed$(EXEEXT) $(js_well_known_types_sources)
+	mkdir -p `dirname $@` && \
 	oldpwd=`pwd` && cd $(srcdir) && \
 	$$oldpwd/js_embed$(EXEEXT) $(js_well_known_types_sources) > $$oldpwd/$@
 
diff --git a/src/google/protobuf/any.pb.h b/src/google/protobuf/any.pb.h
index 40890d41..14c21a8f 100644
--- a/src/google/protobuf/any.pb.h
+++ b/src/google/protobuf/any.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/api.pb.h b/src/google/protobuf/api.pb.h
index b329e1ae..648aa308 100644
--- a/src/google/protobuf/api.pb.h
+++ b/src/google/protobuf/api.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/compiler/cpp/cpp_message.cc b/src/google/protobuf/compiler/cpp/cpp_message.cc
index 8636f089..9b2f090e 100644
--- a/src/google/protobuf/compiler/cpp/cpp_message.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_message.cc
@@ -113,16 +113,16 @@ struct ExtensionRangeSorter {
 bool IsPOD(const FieldDescriptor* field) {
   if (field->is_repeated() || field->is_extension()) return false;
   switch (field->cpp_type()) {
-    case internal::WireFormatLite::CPPTYPE_ENUM:
-    case internal::WireFormatLite::CPPTYPE_INT32:
-    case internal::WireFormatLite::CPPTYPE_INT64:
-    case internal::WireFormatLite::CPPTYPE_UINT32:
-    case internal::WireFormatLite::CPPTYPE_UINT64:
-    case internal::WireFormatLite::CPPTYPE_FLOAT:
-    case internal::WireFormatLite::CPPTYPE_DOUBLE:
-    case internal::WireFormatLite::CPPTYPE_BOOL:
+    case FieldDescriptor::CPPTYPE_ENUM:
+    case FieldDescriptor::CPPTYPE_INT32:
+    case FieldDescriptor::CPPTYPE_INT64:
+    case FieldDescriptor::CPPTYPE_UINT32:
+    case FieldDescriptor::CPPTYPE_UINT64:
+    case FieldDescriptor::CPPTYPE_FLOAT:
+    case FieldDescriptor::CPPTYPE_DOUBLE:
+    case FieldDescriptor::CPPTYPE_BOOL:
       return true;
-    case internal::WireFormatLite::CPPTYPE_STRING:
+    case FieldDescriptor::CPPTYPE_STRING:
       return false;
     default:
       return false;
diff --git a/src/google/protobuf/compiler/plugin.pb.h b/src/google/protobuf/compiler/plugin.pb.h
index 1fb3061a..a6c1300e 100644
--- a/src/google/protobuf/compiler/plugin.pb.h
+++ b/src/google/protobuf/compiler/plugin.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/descriptor.pb.h b/src/google/protobuf/descriptor.pb.h
index ae71d619..4ec0a5b4 100644
--- a/src/google/protobuf/descriptor.pb.h
+++ b/src/google/protobuf/descriptor.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/duration.pb.h b/src/google/protobuf/duration.pb.h
index 376b28f3..7fe0748d 100644
--- a/src/google/protobuf/duration.pb.h
+++ b/src/google/protobuf/duration.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/empty.pb.h b/src/google/protobuf/empty.pb.h
index 505fc3c0..2fef9a43 100644
--- a/src/google/protobuf/empty.pb.h
+++ b/src/google/protobuf/empty.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/field_mask.pb.h b/src/google/protobuf/field_mask.pb.h
index 8773499d..2d75967e 100644
--- a/src/google/protobuf/field_mask.pb.h
+++ b/src/google/protobuf/field_mask.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/message.cc b/src/google/protobuf/message.cc
index a0d3feba..42ec0337 100644
--- a/src/google/protobuf/message.cc
+++ b/src/google/protobuf/message.cc
@@ -170,12 +170,12 @@ size_t Message::SpaceUsedLong() const {
 
 bool Message::SerializeToFileDescriptor(int file_descriptor) const {
   io::FileOutputStream output(file_descriptor);
-  return SerializeToZeroCopyStream(&output);
+  return SerializeToZeroCopyStream(&output) && output.Flush();
 }
 
 bool Message::SerializePartialToFileDescriptor(int file_descriptor) const {
   io::FileOutputStream output(file_descriptor);
-  return SerializePartialToZeroCopyStream(&output);
+  return SerializePartialToZeroCopyStream(&output) && output.Flush();
 }
 
 bool Message::SerializeToOstream(std::ostream* output) const {
diff --git a/src/google/protobuf/source_context.pb.h b/src/google/protobuf/source_context.pb.h
index c974ea89..81893b1a 100644
--- a/src/google/protobuf/source_context.pb.h
+++ b/src/google/protobuf/source_context.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/struct.pb.h b/src/google/protobuf/struct.pb.h
index 8f1b064d..91aa3cf2 100644
--- a/src/google/protobuf/struct.pb.h
+++ b/src/google/protobuf/struct.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index 79bb2396..d11b8100 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -101,7 +101,7 @@ namespace internal {
 
 // The current version, represented as a single integer to make comparison
 // easier:  major * 10^6 + minor * 10^3 + micro
-#define GOOGLE_PROTOBUF_VERSION 3005000
+#define GOOGLE_PROTOBUF_VERSION 3005001
 
 // A suffix string for alpha, beta or rc releases. Empty for stable releases.
 #define GOOGLE_PROTOBUF_VERSION_SUFFIX ""
diff --git a/src/google/protobuf/stubs/io_win32.cc b/src/google/protobuf/stubs/io_win32.cc
index 2b8a8a22..5ead98c8 100644
--- a/src/google/protobuf/stubs/io_win32.cc
+++ b/src/google/protobuf/stubs/io_win32.cc
@@ -30,10 +30,11 @@
 
 // Author: laszlocsomor@google.com (Laszlo Csomor)
 //
-// Implementation for long-path-aware open/mkdir/etc. on Windows.
+// Implementation for long-path-aware open/mkdir/access/etc. on Windows, as well
+// as for the supporting utility functions.
 //
 // These functions convert the input path to an absolute Windows path
-// with "\\?\" prefix if necessary, then pass that to _wopen/_wmkdir/etc.
+// with "\\?\" prefix, then pass that to _wopen/_wmkdir/_waccess/etc.
 // (declared in <io.h>) respectively. This allows working with files/directories
 // whose paths are longer than MAX_PATH (260 chars).
 //
@@ -59,7 +60,6 @@
 #include <google/protobuf/stubs/io_win32.h>
 #include <google/protobuf/stubs/scoped_ptr.h>
 
-#include <cassert>
 #include <memory>
 #include <sstream>
 #include <string>
@@ -89,6 +89,11 @@ struct CharTraits<wchar_t> {
   static bool is_alpha(wchar_t ch) { return iswalpha(ch); }
 };
 
+template <typename char_type>
+bool null_or_empty(const char_type* s) {
+  return s == NULL || *s == 0;
+}
+
 // Returns true if the path starts with a drive letter, e.g. "c:".
 // Note that this won't check for the "\" after the drive letter, so this also
 // returns true for "c:foo" (which is "c:\${PWD}\foo").
@@ -121,16 +126,7 @@ bool is_drive_relative(const char_type* path) {
   return has_drive_letter(path) && (path[2] == 0 || !is_separator(path[2]));
 }
 
-template <typename char_type>
-void replace_directory_separators(char_type* p) {
-  for (; *p; ++p) {
-    if (*p == '/') {
-      *p = '\\';
-    }
-  }
-}
-
-string join_paths(const string& path1, const string& path2) {
+wstring join_paths(const wstring& path1, const wstring& path2) {
   if (path1.empty() || is_path_absolute(path2.c_str()) ||
       has_longpath_prefix(path2.c_str())) {
     return path2;
@@ -144,24 +140,24 @@ string join_paths(const string& path1, const string& path2) {
                                        : (path1 + path2);
   } else {
     return is_separator(path2[0]) ? (path1 + path2)
-                                       : (path1 + '\\' + path2);
+                                       : (path1 + L'\\' + path2);
   }
 }
 
-string normalize(string path) {
+wstring normalize(wstring path) {
   if (has_longpath_prefix(path.c_str())) {
     path = path.substr(4);
   }
 
-  static const string dot(".");
-  static const string dotdot("..");
-  const char *p = path.c_str();
+  static const wstring dot(L".");
+  static const wstring dotdot(L"..");
+  const WCHAR* p = path.c_str();
 
-  std::vector<string> segments;
+  std::vector<wstring> segments;
   int segment_start = -1;
   // Find the path segments in `path` (separated by "/").
   for (int i = 0;; ++i) {
-    if (!is_separator(p[i]) && p[i] != '\0') {
+    if (!is_separator(p[i]) && p[i] != L'\0') {
       // The current character does not end a segment, so start one unless it's
       // already started.
       if (segment_start < 0) {
@@ -170,7 +166,7 @@ string normalize(string path) {
     } else if (segment_start >= 0 && i > segment_start) {
       // The current character is "/" or "\0", so this ends a segment.
       // Add that to `segments` if there's anything to add; handle "." and "..".
-      string segment(p, segment_start, i - segment_start);
+      wstring segment(p, segment_start, i - segment_start);
       segment_start = -1;
       if (segment == dotdot) {
         if (!segments.empty() &&
@@ -181,7 +177,7 @@ string normalize(string path) {
         segments.push_back(segment);
       }
     }
-    if (p[i] == '\0') {
+    if (p[i] == L'\0') {
       break;
     }
   }
@@ -190,64 +186,62 @@ string normalize(string path) {
   // form of it, e.g. "c:\..").
   if (segments.size() == 1 && segments[0].size() == 2 &&
       has_drive_letter(segments[0].c_str())) {
-    return segments[0] + '\\';
+    return segments[0] + L'\\';
   }
 
   // Join all segments.
   bool first = true;
-  std::ostringstream result;
+  std::wstringstream result;
   for (int i = 0; i < segments.size(); ++i) {
     if (!first) {
-      result << '\\';
+      result << L'\\';
     }
     first = false;
     result << segments[i];
   }
   // Preserve trailing separator if the input contained it.
   if (!path.empty() && is_separator(p[path.size() - 1])) {
-    result << '\\';
+    result << L'\\';
   }
   return result.str();
 }
 
-WCHAR* as_wstring(const string& s) {
-  int len = ::MultiByteToWideChar(CP_UTF8, 0, s.c_str(), s.size(), NULL, 0);
-  WCHAR* result = new WCHAR[len + 1];
-  ::MultiByteToWideChar(CP_UTF8, 0, s.c_str(), s.size(), result, len + 1);
-  result[len] = 0;
-  return result;
-}
-
-void as_wchar_path(const string& path, wstring* wchar_path) {
-  scoped_array<WCHAR> wbuf(as_wstring(path));
-  replace_directory_separators(wbuf.get());
-  wchar_path->assign(wbuf.get());
-}
-
-bool as_windows_path(const string& path, wstring* result) {
-  if (path.empty()) {
+bool as_windows_path(const char* path, wstring* result) {
+  if (null_or_empty(path)) {
     result->clear();
     return true;
   }
-  if (is_separator(path[0]) || is_drive_relative(path.c_str())) {
+  wstring wpath;
+  if (!strings::utf8_to_wcs(path, &wpath)) {
+    return false;
+  }
+  if (has_longpath_prefix(wpath.c_str())) {
+    *result = wpath;
+    return true;
+  }
+  if (is_separator(path[0]) || is_drive_relative(path)) {
     return false;
   }
 
-  string mutable_path = path;
-  if (!is_path_absolute(mutable_path.c_str()) &&
-      !has_longpath_prefix(mutable_path.c_str())) {
-    char cwd[MAX_PATH];
-    ::GetCurrentDirectoryA(MAX_PATH, cwd);
-    mutable_path = join_paths(cwd, mutable_path);
+
+  if (!is_path_absolute(wpath.c_str())) {
+    int size = ::GetCurrentDirectoryW(0, NULL);
+    if (size == 0 && GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
+      return false;
+    }
+    scoped_array<WCHAR> wcwd(new WCHAR[size]);
+    ::GetCurrentDirectoryW(size, wcwd.get());
+    wpath = join_paths(wcwd.get(), wpath);
   }
-  as_wchar_path(normalize(mutable_path), result);
-  if (!has_longpath_prefix(result->c_str())) {
+  wpath = normalize(wpath);
+  if (!has_longpath_prefix(wpath.c_str())) {
     // Add the "\\?\" prefix unconditionally. This way we prevent the Win32 API
     // from processing the path and "helpfully" removing trailing dots from the
     // path, for example.
     // See https://github.com/bazelbuild/bazel/issues/2935
-    *result = wstring(L"\\\\?\\") + *result;
+    wpath = wstring(L"\\\\?\\") + wpath;
   }
+  *result = wpath;
   return true;
 }
 
@@ -320,13 +314,21 @@ int stat(const char* path, struct _stat* buffer) {
 
 FILE* fopen(const char* path, const char* mode) {
 #ifdef SUPPORT_LONGPATHS
+  if (null_or_empty(path)) {
+    errno = EINVAL;
+    return NULL;
+  }
   wstring wpath;
   if (!as_windows_path(path, &wpath)) {
     errno = ENOENT;
     return NULL;
   }
-  scoped_array<WCHAR> wmode(as_wstring(mode));
-  return ::_wfopen(wpath.c_str(), wmode.get());
+  wstring wmode;
+  if (!strings::utf8_to_wcs(mode, &wmode)) {
+    errno = EINVAL;
+    return NULL;
+  }
+  return ::_wfopen(wpath.c_str(), wmode.c_str());
 #else
   return ::fopen(path, mode);
 #endif
@@ -348,16 +350,65 @@ int write(int fd, const void* buffer, size_t size) {
   return ::_write(fd, buffer, size);
 }
 
-wstring testonly_path_to_winpath(const string& path) {
+wstring testonly_utf8_to_winpath(const char* path) {
   wstring wpath;
-  as_windows_path(path, &wpath);
-  return wpath;
+  return as_windows_path(path, &wpath) ? wpath : wstring();
+}
+
+namespace strings {
+
+bool wcs_to_mbs(const WCHAR* s, string* out, bool outUtf8) {
+  if (null_or_empty(s)) {
+    out->clear();
+    return true;
+  }
+  BOOL usedDefaultChar = FALSE;
+  SetLastError(0);
+  int size = WideCharToMultiByte(
+      outUtf8 ? CP_UTF8 : CP_ACP, 0, s, -1, NULL, 0, NULL,
+      outUtf8 ? NULL : &usedDefaultChar);
+  if ((size == 0 && GetLastError() != ERROR_INSUFFICIENT_BUFFER)
+      || usedDefaultChar) {
+    return false;
+  }
+  scoped_array<CHAR> astr(new CHAR[size]);
+  WideCharToMultiByte(
+      outUtf8 ? CP_UTF8 : CP_ACP, 0, s, -1, astr.get(), size, NULL, NULL);
+  out->assign(astr.get());
+  return true;
+}
+
+bool mbs_to_wcs(const char* s, wstring* out, bool inUtf8) {
+  if (null_or_empty(s)) {
+    out->clear();
+    return true;
+  }
+
+  SetLastError(0);
+  int size =
+      MultiByteToWideChar(inUtf8 ? CP_UTF8 : CP_ACP, 0, s, -1, NULL, 0);
+  if (size == 0 && GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
+    return false;
+  }
+  scoped_array<WCHAR> wstr(new WCHAR[size]);
+  MultiByteToWideChar(
+      inUtf8 ? CP_UTF8 : CP_ACP, 0, s, -1, wstr.get(), size + 1);
+  out->assign(wstr.get());
+  return true;
 }
 
+bool utf8_to_wcs(const char* input, wstring* out) {
+  return mbs_to_wcs(input, out, true);
+}
+
+bool wcs_to_utf8(const wchar_t* input, string* out) {
+  return wcs_to_mbs(input, out, true);
+}
+
+}  // namespace strings
 }  // namespace win32
 }  // namespace internal
 }  // namespace protobuf
 }  // namespace google
 
 #endif  // defined(_WIN32)
-
diff --git a/src/google/protobuf/stubs/io_win32.h b/src/google/protobuf/stubs/io_win32.h
index 53160089..9e17d253 100644
--- a/src/google/protobuf/stubs/io_win32.h
+++ b/src/google/protobuf/stubs/io_win32.h
@@ -69,8 +69,25 @@ LIBPROTOBUF_EXPORT int read(int fd, void* buffer, size_t size);
 LIBPROTOBUF_EXPORT int setmode(int fd, int mode);
 LIBPROTOBUF_EXPORT int stat(const char* path, struct _stat* buffer);
 LIBPROTOBUF_EXPORT int write(int fd, const void* buffer, size_t size);
-LIBPROTOBUF_EXPORT std::wstring testonly_path_to_winpath(
-    const std::string& path);
+LIBPROTOBUF_EXPORT std::wstring testonly_utf8_to_winpath(const char* path);
+
+namespace strings {
+
+// Convert from UTF-16 to Active-Code-Page-encoded or to UTF-8-encoded text.
+LIBPROTOBUF_EXPORT bool wcs_to_mbs(
+    const wchar_t* s, std::string* out, bool outUtf8);
+
+// Convert from Active-Code-Page-encoded or UTF-8-encoded text to UTF-16.
+LIBPROTOBUF_EXPORT bool mbs_to_wcs(
+    const char* s, std::wstring* out, bool inUtf8);
+
+// Convert from UTF-8-encoded text to UTF-16.
+LIBPROTOBUF_EXPORT bool utf8_to_wcs(const char* input, std::wstring* out);
+
+// Convert from UTF-16-encoded text to UTF-8.
+LIBPROTOBUF_EXPORT bool wcs_to_utf8(const wchar_t* input, std::string* out);
+
+}  // namespace strings
 
 }  // namespace win32
 }  // namespace internal
diff --git a/src/google/protobuf/stubs/io_win32_unittest.cc b/src/google/protobuf/stubs/io_win32_unittest.cc
index ce6f7162..b216aece 100644
--- a/src/google/protobuf/stubs/io_win32_unittest.cc
+++ b/src/google/protobuf/stubs/io_win32_unittest.cc
@@ -30,7 +30,8 @@
 
 // Author: laszlocsomor@google.com (Laszlo Csomor)
 //
-// Unit tests for long-path-aware open/mkdir/access on Windows.
+// Unit tests for long-path-aware open/mkdir/access/etc. on Windows, as well as
+// for the supporting utility functions.
 //
 // This file is only used on Windows, it's empty on other platforms.
 
@@ -48,7 +49,6 @@
 
 #include <google/protobuf/stubs/io_win32.h>
 #include <google/protobuf/stubs/scoped_ptr.h>
-#include <google/protobuf/testing/googletest.h>
 #include <gtest/gtest.h>
 
 #include <memory>
@@ -61,6 +61,27 @@ namespace internal {
 namespace win32 {
 namespace {
 
+const char kUtf8Text[] = {
+    'h', 'i', ' ',
+    // utf-8: 11010000 10011111, utf-16: 100 0001 1111 = 0x041F
+    0xd0, 0x9f,
+    // utf-8: 11010001 10000000, utf-16: 100 0100 0000 = 0x0440
+    0xd1, 0x80,
+    // utf-8: 11010000 10111000, utf-16: 100 0011 1000 = 0x0438
+    0xd0, 0xb8,
+    // utf-8: 11010000 10110010, utf-16: 100 0011 0010 = 0x0432
+    0xd0, 0xb2,
+    // utf-8: 11010000 10110101, utf-16: 100 0011 0101 = 0x0435
+    0xd0, 0xb5,
+    // utf-8: 11010001 10000010, utf-16: 100 0100 0010 = 0x0442
+    0xd1, 0x82, 0
+};
+
+const wchar_t kUtf16Text[] = {
+  L'h', L'i', L' ',
+  L'\x41f', L'\x440', L'\x438', L'\x432', L'\x435', L'\x442', 0
+};
+
 using std::string;
 using std::wstring;
 
@@ -73,6 +94,7 @@ class IoWin32Test : public ::testing::Test {
   bool CreateAllUnder(wstring path);
   bool DeleteAllUnder(wstring path);
 
+  WCHAR working_directory[MAX_PATH];
   string test_tmpdir;
   wstring wtest_tmpdir;
 };
@@ -89,71 +111,88 @@ void StripTrailingSlashes(string* str) {
   for (; i >= 0 && ((*str)[i] == '/' || (*str)[i] == '\\'); --i) {}
   str->resize(i+1);
 }
+
+bool GetEnvVarAsUtf8(const WCHAR* name, string* result) {
+  DWORD size = ::GetEnvironmentVariableW(name, NULL, 0);
+  if (size > 0 && GetLastError() != ERROR_ENVVAR_NOT_FOUND) {
+    scoped_array<WCHAR> wcs(new WCHAR[size]);
+    ::GetEnvironmentVariableW(name, wcs.get(), size);
+    // GetEnvironmentVariableA retrieves an Active-Code-Page-encoded text which
+    // we'd first need to convert to UTF-16 then to UTF-8, because there seems
+    // to be no API function to do that conversion directly.
+    // GetEnvironmentVariableW retrieves an UTF-16-encoded text, which we need
+    // to convert to UTF-8.
+    return strings::wcs_to_utf8(wcs.get(), result);
+  } else {
+    return false;
+  }
+}
+
+bool GetCwdAsUtf8(string* result) {
+  DWORD size = ::GetCurrentDirectoryW(0, NULL);
+  if (size > 0) {
+    scoped_array<WCHAR> wcs(new WCHAR[size]);
+    ::GetCurrentDirectoryW(size, wcs.get());
+    // GetCurrentDirectoryA retrieves an Active-Code-Page-encoded text which
+    // we'd first need to convert to UTF-16 then to UTF-8, because there seems
+    // to be no API function to do that conversion directly.
+    // GetCurrentDirectoryW retrieves an UTF-16-encoded text, which we need
+    // to convert to UTF-8.
+    return strings::wcs_to_utf8(wcs.get(), result);
+  } else {
+    return false;
+  }
+}
+
 }  // namespace
 
 void IoWin32Test::SetUp() {
-  test_tmpdir = string(TestTempDir());
+  test_tmpdir.clear();
   wtest_tmpdir.clear();
-  if (test_tmpdir.empty()) {
-    const char* test_tmpdir_env = getenv("TEST_TMPDIR");
-    if (test_tmpdir_env != NULL && *test_tmpdir_env) {
-      test_tmpdir = string(test_tmpdir_env);
-    }
-
-    // Only Bazel defines TEST_TMPDIR, CMake does not, so look for other
-    // suitable environment variables.
-    if (test_tmpdir.empty()) {
-      static const char* names[] = {"TEMP", "TMP"};
-      for (int i = 0; i < sizeof(names)/sizeof(names[0]); ++i) {
-        const char* name = names[i];
-        test_tmpdir_env = getenv(name);
-        if (test_tmpdir_env != NULL && *test_tmpdir_env) {
-          test_tmpdir = string(test_tmpdir_env);
-          break;
-        }
-      }
-    }
+  EXPECT_GT(::GetCurrentDirectoryW(MAX_PATH, working_directory), 0);
 
-    // No other temp directory was found. Use the current director
-    if (test_tmpdir.empty()) {
-      char buffer[MAX_PATH];
-      // Use GetCurrentDirectoryA instead of GetCurrentDirectoryW, because the
-      // current working directory must always be shorter than MAX_PATH, even
-      // with
-      // "\\?\" prefix (except on Windows 10 version 1607 and beyond, after
-      // opting in to long paths by default [1]).
-      //
-      // [1] https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#maxpath
-      DWORD result = ::GetCurrentDirectoryA(MAX_PATH, buffer);
-      if (result > 0) {
-        test_tmpdir = string(buffer);
-      } else {
-        // Using assertions in SetUp/TearDown seems to confuse the test
-        // framework, so just leave the member variables empty in case of
-        // failure.
-        GOOGLE_CHECK_OK(false);
-        return;
-      }
-    }
+  string tmp;
+  bool ok = false;
+  if (!ok) {
+    // Bazel sets this environment variable when it runs tests.
+    ok = GetEnvVarAsUtf8(L"TEST_TMPDIR", &tmp);
   }
-
-  StripTrailingSlashes(&test_tmpdir);
-  test_tmpdir += "\\io_win32_unittest.tmp";
-
-  // CreateDirectoryA's limit is 248 chars, see MSDN.
-  // https://msdn.microsoft.com/en-us/library/windows/desktop/aa363855(v=vs.85).aspx
-  wtest_tmpdir = testonly_path_to_winpath(test_tmpdir);
-  if (!DeleteAllUnder(wtest_tmpdir) || !CreateAllUnder(wtest_tmpdir)) {
-    GOOGLE_CHECK_OK(false);
-    test_tmpdir.clear();
-    wtest_tmpdir.clear();
+  if (!ok) {
+    // Bazel 0.8.0 sets this environment for every build and test action.
+    ok = GetEnvVarAsUtf8(L"TEMP", &tmp);
   }
+  if (!ok) {
+    // Bazel 0.8.0 sets this environment for every build and test action.
+    ok = GetEnvVarAsUtf8(L"TMP", &tmp);
+  }
+  if (!ok) {
+    // Fall back to using the current directory.
+    ok = GetCwdAsUtf8(&tmp);
+  }
+  if (!ok || tmp.empty()) {
+    FAIL() << "Cannot find a temp directory.";
+  }
+
+  StripTrailingSlashes(&tmp);
+  std::stringstream result;
+  // Deleting files and directories is asynchronous on Windows, and if TearDown
+  // just deleted the previous temp directory, sometimes we cannot recreate the
+  // same directory.
+  // Use a counter so every test method gets its own temp directory.
+  static unsigned int counter = 0;
+  result << tmp << "\\w32tst" << counter++ << ".tmp";
+  test_tmpdir = result.str();
+  wtest_tmpdir = testonly_utf8_to_winpath(test_tmpdir.c_str());
+  ASSERT_FALSE(wtest_tmpdir.empty());
+  ASSERT_TRUE(DeleteAllUnder(wtest_tmpdir));
+  ASSERT_TRUE(CreateAllUnder(wtest_tmpdir));
 }
 
 void IoWin32Test::TearDown() {
   if (!wtest_tmpdir.empty()) {
     DeleteAllUnder(wtest_tmpdir);
   }
+  ::SetCurrentDirectoryW(working_directory);
 }
 
 bool IoWin32Test::CreateAllUnder(wstring path) {
@@ -191,8 +230,8 @@ bool IoWin32Test::DeleteAllUnder(wstring path) {
     path = wstring(L"\\\\?\\") + path;
   }
   // Append "\" if necessary.
-  if (path[path.size() - 1] != '\\') {
-    path.push_back('\\');
+  if (path[path.size() - 1] != L'\\') {
+    path.push_back(L'\\');
   }
 
   WIN32_FIND_DATAW metadata;
@@ -309,13 +348,24 @@ TEST_F(IoWin32Test, MkdirTest) {
   ASSERT_EQ(errno, ENOENT);
 }
 
+TEST_F(IoWin32Test, MkdirTestNonAscii) {
+  ASSERT_INITIALIZED;
+
+  // Create a non-ASCII path.
+  // Ensure that we can create the directory using SetCurrentDirectoryW.
+  EXPECT_TRUE(CreateDirectoryW((wtest_tmpdir + L"\\1").c_str(), NULL));
+  EXPECT_TRUE(CreateDirectoryW((wtest_tmpdir + L"\\1\\" + kUtf16Text).c_str(), NULL));
+  // Ensure that we can create a very similarly named directory using mkdir.
+  // We don't attemp to delete and recreate the same directory, because on
+  // Windows, deleting files and directories seems to be asynchronous.
+  EXPECT_EQ(mkdir((test_tmpdir + "\\2").c_str(), 0644), 0);
+  EXPECT_EQ(mkdir((test_tmpdir + "\\2\\" + kUtf8Text).c_str(), 0644), 0);
+}
+
 TEST_F(IoWin32Test, ChdirTest) {
-  char owd[MAX_PATH];
-  EXPECT_GT(::GetCurrentDirectoryA(MAX_PATH, owd), 0);
   string path("C:\\");
   EXPECT_EQ(access(path.c_str(), F_OK), 0);
   ASSERT_EQ(chdir(path.c_str()), 0);
-  EXPECT_TRUE(::SetCurrentDirectoryA(owd));
 
   // Do not try to chdir into the test_tmpdir, it may already contain directory
   // names with trailing dots.
@@ -330,17 +380,37 @@ TEST_F(IoWin32Test, ChdirTest) {
   ASSERT_NE(chdir(path.c_str()), 0);
 }
 
+TEST_F(IoWin32Test, ChdirTestNonAscii) {
+  ASSERT_INITIALIZED;
+
+  // Create a directory with a non-ASCII path and ensure we can cd into it.
+  wstring wNonAscii(wtest_tmpdir + L"\\" + kUtf16Text);
+  string nonAscii;
+  EXPECT_TRUE(strings::wcs_to_utf8(wNonAscii.c_str(), &nonAscii));
+  EXPECT_TRUE(CreateDirectoryW(wNonAscii.c_str(), NULL));
+  WCHAR cwd[MAX_PATH];
+  EXPECT_TRUE(GetCurrentDirectoryW(MAX_PATH, cwd));
+  // Ensure that we can cd into the path using SetCurrentDirectoryW.
+  EXPECT_TRUE(SetCurrentDirectoryW(wNonAscii.c_str()));
+  EXPECT_TRUE(SetCurrentDirectoryW(cwd));
+  // Ensure that we can cd into the path using chdir.
+  ASSERT_EQ(chdir(nonAscii.c_str()), 0);
+  // Ensure that the GetCurrentDirectoryW returns the desired path.
+  EXPECT_TRUE(GetCurrentDirectoryW(MAX_PATH, cwd));
+  ASSERT_EQ(wNonAscii, cwd);
+}
+
 TEST_F(IoWin32Test, AsWindowsPathTest) {
   DWORD size = GetCurrentDirectoryW(0, NULL);
   scoped_array<wchar_t> cwd_str(new wchar_t[size]);
   EXPECT_GT(GetCurrentDirectoryW(size, cwd_str.get()), 0);
   wstring cwd = wstring(L"\\\\?\\") + cwd_str.get();
 
-  ASSERT_EQ(testonly_path_to_winpath("relative_mkdirtest"),
+  ASSERT_EQ(testonly_utf8_to_winpath("relative_mkdirtest"),
             cwd + L"\\relative_mkdirtest");
-  ASSERT_EQ(testonly_path_to_winpath("preserve//\\trailing///"),
+  ASSERT_EQ(testonly_utf8_to_winpath("preserve//\\trailing///"),
             cwd + L"\\preserve\\trailing\\");
-  ASSERT_EQ(testonly_path_to_winpath("./normalize_me\\/../blah"),
+  ASSERT_EQ(testonly_utf8_to_winpath("./normalize_me\\/../blah"),
             cwd + L"\\blah");
   std::ostringstream relpath;
   for (wchar_t* p = cwd_str.get(); *p; ++p) {
@@ -349,18 +419,28 @@ TEST_F(IoWin32Test, AsWindowsPathTest) {
     }
   }
   relpath << ".\\/../\\./beyond-toplevel";
-  ASSERT_EQ(testonly_path_to_winpath(relpath.str()),
+  ASSERT_EQ(testonly_utf8_to_winpath(relpath.str().c_str()),
             wstring(L"\\\\?\\") + cwd_str.get()[0] + L":\\beyond-toplevel");
 
   // Absolute unix paths lack drive letters, driveless absolute windows paths
   // do too. Neither can be converted to a drive-specifying absolute Windows
   // path.
-  ASSERT_EQ(testonly_path_to_winpath("/absolute/unix/path"), L"");
+  ASSERT_EQ(testonly_utf8_to_winpath("/absolute/unix/path"), L"");
   // Though valid on Windows, we also don't support UNC paths (\\UNC\\blah).
-  ASSERT_EQ(testonly_path_to_winpath("\\driveless\\absolute"), L"");
+  ASSERT_EQ(testonly_utf8_to_winpath("\\driveless\\absolute"), L"");
   // Though valid in cmd.exe, drive-relative paths are not supported.
-  ASSERT_EQ(testonly_path_to_winpath("c:foo"), L"");
-  ASSERT_EQ(testonly_path_to_winpath("c:/foo"), L"\\\\?\\c:\\foo");
+  ASSERT_EQ(testonly_utf8_to_winpath("c:foo"), L"");
+  ASSERT_EQ(testonly_utf8_to_winpath("c:/foo"), L"\\\\?\\c:\\foo");
+  ASSERT_EQ(testonly_utf8_to_winpath("\\\\?\\C:\\foo"), L"\\\\?\\C:\\foo");
+}
+
+TEST_F(IoWin32Test, Utf8Utf16ConversionTest) {
+  string mbs;
+  wstring wcs;
+  ASSERT_TRUE(strings::utf8_to_wcs(kUtf8Text, &wcs));
+  ASSERT_TRUE(strings::wcs_to_utf8(kUtf16Text, &mbs));
+  ASSERT_EQ(wcs, kUtf16Text);
+  ASSERT_EQ(mbs, kUtf8Text);
 }
 
 }  // namespace
diff --git a/src/google/protobuf/testing/googletest.cc b/src/google/protobuf/testing/googletest.cc
index c329b6c1..b81d3994 100644
--- a/src/google/protobuf/testing/googletest.cc
+++ b/src/google/protobuf/testing/googletest.cc
@@ -132,7 +132,7 @@ string GetTemporaryDirectoryName() {
   // with "\\?\") but these will be degenerate in the sense that you cannot
   // chdir into such directories (or navigate into them with Windows Explorer)
   // nor can you open such files with some programs (e.g. Notepad).
-  if (result.back() == '.') {
+  if (result[result.size() - 1] == '.') {
     result[result.size() - 1] = '_';
   }
   // On Win32, tmpnam() returns a file prefixed with '\', but which is supposed
diff --git a/src/google/protobuf/timestamp.pb.h b/src/google/protobuf/timestamp.pb.h
index 8e5911fe..a0f9605c 100644
--- a/src/google/protobuf/timestamp.pb.h
+++ b/src/google/protobuf/timestamp.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/type.pb.h b/src/google/protobuf/type.pb.h
index c5e800c3..49bed8ee 100644
--- a/src/google/protobuf/type.pb.h
+++ b/src/google/protobuf/type.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.
diff --git a/src/google/protobuf/util/field_mask_util.cc b/src/google/protobuf/util/field_mask_util.cc
index 4d0d3a46..8a413498 100644
--- a/src/google/protobuf/util/field_mask_util.cc
+++ b/src/google/protobuf/util/field_mask_util.cc
@@ -374,7 +374,7 @@ void FieldMaskTree::RemovePath(const string& path,
       }
     }
     if (ContainsKey(node->children, parts[i])) {
-      node = node->children.at(parts[i]);
+      node = node->children[parts[i]];
       if (field_descriptor->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) {
         current_descriptor = field_descriptor->message_type();
       }
diff --git a/src/google/protobuf/wrappers.pb.h b/src/google/protobuf/wrappers.pb.h
index e533ca1d..876bf39b 100644
--- a/src/google/protobuf/wrappers.pb.h
+++ b/src/google/protobuf/wrappers.pb.h
@@ -13,7 +13,7 @@
 #error incompatible with your Protocol Buffer headers.  Please update
 #error your headers.
 #endif
-#if 3005000 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
+#if 3005001 < GOOGLE_PROTOBUF_MIN_PROTOC_VERSION
 #error This file was generated by an older version of protoc which is
 #error incompatible with your Protocol Buffer headers.  Please
 #error regenerate this file with a newer version of protoc.