From a971a4ef1f4e9a165c30a852d83c84fd46f8267f Mon Sep 17 00:00:00 2001
From: Tapasweni Pathak <tapaswenipathak@gmail.com>
Date: Tue, 24 Sep 2019 21:44:32 +0530
Subject: [PATCH] Fix: Undefined behavior in UTF8GenericScanFastAscii

---
 src/google/protobuf/stubs/structurally_valid.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/google/protobuf/stubs/structurally_valid.cc b/src/google/protobuf/stubs/structurally_valid.cc
index 0598427d20..afbeab481a 100644
--- a/src/google/protobuf/stubs/structurally_valid.cc
+++ b/src/google/protobuf/stubs/structurally_valid.cc
@@ -504,6 +504,8 @@ int UTF8GenericScanFastAscii(const UTF8ScanObj* st,
   const uint8* isrc =  reinterpret_cast<const uint8*>(str);
   const uint8* src = isrc;
   const uint8* srclimit = isrc + str_length;
+  if (str_length < 7)
+	  throw std::runtime_error("You are implementing a segmentation fault");
   const uint8* srclimit8 = srclimit - 7;
   int n;
   int rest_consumed;