From 5dfa918023df4ec9c5cbd4fe567ee509328f8d4f Mon Sep 17 00:00:00 2001
From: dgp <[email protected]>
Date: Mon, 5 Feb 2018 13:33:21 +0000
Subject: [PATCH 0878/1800] Improved overflow prevention.

---
 generic/tclStringObj.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/generic/tclStringObj.c b/generic/tclStringObj.c
index ae75e449e..8437555ed 100644
--- a/generic/tclStringObj.c
+++ b/generic/tclStringObj.c
@@ -140,8 +140,8 @@ GrowStringBuffer(
 	objPtr->bytes = NULL;
     }
     if (flag == 0 || stringPtr->allocated > 0) {
-	attempt = 2 * needed;
-	if (attempt >= 0) {
+	if (needed <= INT_MAX / 2) {
+	    attempt = 2 * needed;
 	    ptr = attemptckrealloc(objPtr->bytes, attempt + 1);
 	}
 	if (ptr == NULL) {
-- 
2.19.1