Use protoc version for --version

src/google/protobuf/compiler/command_line_interface.cc

@@ -1844,7 +1844,7 @@ CommandLineInterface::InterpretArgument(const std::string& name,
     if (!version_info_.empty()) {
       std::cout << version_info_ << std::endl;
     }
-    std::cout << "libprotoc " << internal::VersionString(PROTOBUF_VERSION)
+    std::cout << "libprotoc " << internal::ProtocVersionString(PROTOBUF_VERSION)
               << PROTOBUF_VERSION_SUFFIX << std::endl;
     return PARSE_ARGUMENT_DONE_AND_EXIT;  // Exit without running compiler.
 

src/google/protobuf/stubs/common.cc

@@ -108,6 +108,22 @@ std::string VersionString(int version) {
   return buffer;
 }
 
+std::string ProtocVersionString(int version) {
+  int minor = (version / 1000) % 1000;
+  int micro = version % 1000;
+
+  // 128 bytes should always be enough, but we use snprintf() anyway to be
+  // safe.
+  char buffer[128];
+  snprintf(buffer, sizeof(buffer), "%d.%d", minor, micro);
+
+  // Guard against broken MSVC snprintf().
+  buffer[sizeof(buffer)-1] = '\0';
+
+  return buffer;
+
+}
+
 }  // namespace internal
 
 // ===================================================================

src/google/protobuf/stubs/common.h

@@ -108,6 +108,9 @@ void PROTOBUF_EXPORT VerifyVersion(int headerVersion, int minLibraryVersion,
 // Converts a numeric version number to a string.
 std::string PROTOBUF_EXPORT VersionString(int version);
 
+// Prints the protoc compiler version (no major version)
+std::string PROTOBUF_EXPORT ProtocVersionString(int version);
+
 }  // namespace internal
 
 // Place this macro in your main() function (or somewhere before you attempt