From 6a3374989c40b060b19d1c1ac1b1a63c0c0819ed Mon Sep 17 00:00:00 2001
From: Pascal Cuoq <cuoq@trust-in-soft.com>
Date: Sun, 15 May 2016 19:11:55 +0200
Subject: [PATCH] Avoid undefined behavior when computing larger blockSize. The
 compiler might reason that (end - start)*2 is negative only if (end - start)
 is negative, see https://godbolt.org/g/wVEoTM

---
 src/expat/lib/xmlparse.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/expat/lib/xmlparse.c b/src/expat/lib/xmlparse.c
index 09c9875844..373aa4b38b 100644
--- a/src/expat/lib/xmlparse.c
+++ b/src/expat/lib/xmlparse.c
@@ -6264,7 +6264,7 @@ poolGrow(STRING_POOL *pool)
   }
   if (pool->blocks && pool->start == pool->blocks->s) {
     BLOCK *temp;
-    int blockSize = (int)(pool->end - pool->start)*2;
+    int blockSize = (int)((unsigned)(pool->end - pool->start)*2U);
 
     if (blockSize < 0)
       return XML_FALSE;