From 06e950ecb21514b0d09f942c108ad346102278f1 Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Thu, 26 Apr 2012 20:54:27 +0000
Subject: [PATCH] Defensively guard against calling malloc() with a size of
 zero.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155661 91177308-0d34-0410-b5e6-96231b3b80d8
---
 runtime/libprofile/CommonProfiling.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/runtime/libprofile/CommonProfiling.c b/runtime/libprofile/CommonProfiling.c
index d55f51c5b44..13e3eb9cf7b 100644
--- a/runtime/libprofile/CommonProfiling.c
+++ b/runtime/libprofile/CommonProfiling.c
@@ -65,6 +65,15 @@ int save_arguments(int argc, const char **argv) {
   for (Length = 0, i = 0; i != (unsigned)argc; ++i)
     Length += strlen(argv[i])+1;
 
+  // Defensively check for a zero length, even though this is unlikely
+  // to happen in practice.  This avoids calling malloc() below with a
+  // size of 0.
+  if (Length == 0) {
+    SavedArgs = 0;
+    SavedArgsLength = 0;
+    return argc;
+  }
+  
   SavedArgs = (char*)malloc(Length);
   for (Length = 0, i = 0; i != (unsigned)argc; ++i) {
     unsigned Len = strlen(argv[i]);