From 30aed67d4e0073c84846802a734dbbcd02334ff6 Mon Sep 17 00:00:00 2001
From: Asra Ali <asraa@google.com>
Date: Thu, 20 Jun 2019 13:09:02 -0400
Subject: [PATCH] fix ubsan warning

Signed-off-by: Asra Ali <asraa@google.com>
---
 src/google/protobuf/stubs/strutil.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/google/protobuf/stubs/strutil.cc b/src/google/protobuf/stubs/strutil.cc
index 3844fa6b8b6..5486887295f 100644
--- a/src/google/protobuf/stubs/strutil.cc
+++ b/src/google/protobuf/stubs/strutil.cc
@@ -1065,10 +1065,12 @@ char* FastUInt32ToBufferLeft(uint32 u, char* buffer) {
 }
 
 char* FastInt32ToBufferLeft(int32 i, char* buffer) {
-  uint32 u = i;
+  uint32 u = 0;
   if (i < 0) {
     *buffer++ = '-';
-    u = -i;
+    u -= i;
+  } else {
+    u = i;
   }
   return FastUInt32ToBufferLeft(u, buffer);
 }