diff -ru protobuf2/src/google/protobuf/compiler/cpp/cpp_message.cc protobuf/src/google/protobuf/compiler/cpp/cpp_message.cc
--- protobuf2/src/google/protobuf/compiler/cpp/cpp_message.cc	2017-07-20 11:08:08.427529526 -0700
+++ protobuf/src/google/protobuf/compiler/cpp/cpp_message.cc	2017-07-20 11:12:21.215840768 -0700
@@ -3394,8 +3394,8 @@
 
       // Emit code to parse the common, expected case.
       printer->Print("if (static_cast< ::google::protobuf::uint8>(tag) ==\n"
-                     "    static_cast< ::google::protobuf::uint8>($commontag$u)) {\n",
-          "commontag", SimpleItoa(WireFormat::MakeTag(field)));
+                     "    static_cast< ::google::protobuf::uint8>($truncated$u)) {\n",
+          "truncated", SimpleItoa(WireFormat::MakeTag(field) & 0xFF));
 
       printer->Indent();
       if (field->is_packed()) {
@@ -3409,22 +3409,22 @@
       if (field->is_packed()) {
         internal::WireFormatLite::WireType wiretype =
             WireFormat::WireTypeForFieldType(field->type());
+        const uint32 tag = internal::WireFormatLite::MakeTag(
+            field->number(), wiretype);
         printer->Print("} else if (static_cast< ::google::protobuf::uint8>(tag) ==\n"
-                       "           static_cast< ::google::protobuf::uint8>($uncommontag$u)) {\n",
-                       "uncommontag", SimpleItoa(
-                           internal::WireFormatLite::MakeTag(
-                               field->number(), wiretype)));
+                       "           static_cast< ::google::protobuf::uint8>($truncated$u)) {\n",
+                       "truncated", SimpleItoa(tag & 0xFF));
         printer->Indent();
         field_generator.GenerateMergeFromCodedStream(printer);
         printer->Outdent();
       } else if (field->is_packable() && !field->is_packed()) {
         internal::WireFormatLite::WireType wiretype =
             internal::WireFormatLite::WIRETYPE_LENGTH_DELIMITED;
+        const uint32 tag = internal::WireFormatLite::MakeTag(
+            field->number(), wiretype);
         printer->Print("} else if (static_cast< ::google::protobuf::uint8>(tag) ==\n"
-                       "           static_cast< ::google::protobuf::uint8>($uncommontag$u)) {\n",
-                       "uncommontag", SimpleItoa(
-                           internal::WireFormatLite::MakeTag(
-                               field->number(), wiretype)));
+                       "           static_cast< ::google::protobuf::uint8>($truncated$u)) {\n",
+                       "truncated", SimpleItoa(tag & 0xFF));
         printer->Indent();
         field_generator.GenerateMergeFromCodedStreamWithPacking(printer);
         printer->Outdent();
diff -ru protobuf2/src/google/protobuf/descriptor.pb.cc protobuf/src/google/protobuf/descriptor.pb.cc
--- protobuf2/src/google/protobuf/descriptor.pb.cc	2017-07-20 11:08:08.419529516 -0700
+++ protobuf/src/google/protobuf/descriptor.pb.cc	2017-07-20 11:20:23.248428561 -0700
@@ -8684,7 +8684,7 @@
       // optional string objc_class_prefix = 36;
       case 36: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(290u)) {
+            static_cast< ::google::protobuf::uint8>(0x22u)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadString(
                 input, this->mutable_objc_class_prefix()));
           ::google::protobuf::internal::WireFormat::VerifyUTF8StringNamedField(
@@ -8700,7 +8700,7 @@
       // optional string csharp_namespace = 37;
       case 37: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(298u)) {
+            static_cast< ::google::protobuf::uint8>(0x28u)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadString(
                 input, this->mutable_csharp_namespace()));
           ::google::protobuf::internal::WireFormat::VerifyUTF8StringNamedField(
@@ -8716,7 +8716,7 @@
       // optional string swift_prefix = 39;
       case 39: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(314u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadString(
                 input, this->mutable_swift_prefix()));
           ::google::protobuf::internal::WireFormat::VerifyUTF8StringNamedField(
@@ -8732,7 +8732,7 @@
       // optional string php_class_prefix = 40;
       case 40: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(322u)) {
+            static_cast< ::google::protobuf::uint8>(0x42u)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadString(
                 input, this->mutable_php_class_prefix()));
           ::google::protobuf::internal::WireFormat::VerifyUTF8StringNamedField(
@@ -8748,7 +8748,7 @@
       // optional string php_namespace = 41;
       case 41: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(330u)) {
+            static_cast< ::google::protobuf::uint8>(0x4au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadString(
                 input, this->mutable_php_namespace()));
           ::google::protobuf::internal::WireFormat::VerifyUTF8StringNamedField(
@@ -8764,7 +8764,7 @@
       // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
       case 999: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(7994u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(
                 input, add_uninterpreted_option()));
         } else {
@@ -10352,7 +10352,7 @@
       // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
       case 999: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(7994u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(
                 input, add_uninterpreted_option()));
         } else {
@@ -10943,7 +10943,7 @@
       // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
       case 999: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(7994u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(
                 input, add_uninterpreted_option()));
         } else {
@@ -11515,7 +11515,7 @@
       // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
       case 999: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(7994u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(
                 input, add_uninterpreted_option()));
         } else {
@@ -11854,7 +11854,7 @@
       // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
       case 999: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(7994u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(
                 input, add_uninterpreted_option()));
         } else {
@@ -12264,7 +12264,7 @@
       // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
       case 999: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(7994u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(
                 input, add_uninterpreted_option()));
         } else {
@@ -12611,7 +12611,7 @@
       // optional bool deprecated = 33 [default = false];
       case 33: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(264u)) {
+            static_cast< ::google::protobuf::uint8>(0x08u)) {
           set_has_deprecated();
           DO_((::google::protobuf::internal::WireFormatLite::ReadPrimitive<
                    bool, ::google::protobuf::internal::WireFormatLite::TYPE_BOOL>(
@@ -12625,7 +12625,7 @@
       // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
       case 999: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(7994u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(
                 input, add_uninterpreted_option()));
         } else {
@@ -12981,7 +12981,7 @@
       // optional bool deprecated = 33 [default = false];
       case 33: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(264u)) {
+            static_cast< ::google::protobuf::uint8>(0x08u)) {
           set_has_deprecated();
           DO_((::google::protobuf::internal::WireFormatLite::ReadPrimitive<
                    bool, ::google::protobuf::internal::WireFormatLite::TYPE_BOOL>(
@@ -12995,7 +12995,7 @@
       // optional .google.protobuf.MethodOptions.IdempotencyLevel idempotency_level = 34 [default = IDEMPOTENCY_UNKNOWN];
       case 34: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(272u)) {
+            static_cast< ::google::protobuf::uint8>(0x10u)) {
           int value;
           DO_((::google::protobuf::internal::WireFormatLite::ReadPrimitive<
                    int, ::google::protobuf::internal::WireFormatLite::TYPE_ENUM>(
@@ -13015,7 +13015,7 @@
       // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
       case 999: {
         if (static_cast< ::google::protobuf::uint8>(tag) ==
-            static_cast< ::google::protobuf::uint8>(7994u)) {
+            static_cast< ::google::protobuf::uint8>(0x3au)) {
           DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(
                 input, add_uninterpreted_option()));
         } else {