From: David Herrmann <dh.herrmann@gmail.com>
Date: Fri, 13 Jun 2014 16:38:15 +0000 (+0200)
Subject: util: fix multiply-alloc helpers with size==0
X-Git-Tag: v215~411
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=368504f485d09b9fd48b7538e71981f648eb32bb;p=elogind.git

util: fix multiply-alloc helpers with size==0

Passing 0 to malloc() is not required to return NULL. Therefore, don't
bail out if "b" is 0. This is not of importance to the existing helpers,
but the upcoming realloc_multiply() requires this. To keep consistence, we
keep the same behavior for the other helpers.
---

diff --git a/src/shared/util.h b/src/shared/util.h
index e8552410c..5a2f10387 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -666,14 +666,14 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, endmntent);
 #define _cleanup_close_pair_ _cleanup_(close_pairp)
 
 _malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t a, size_t b) {
-        if (_unlikely_(b == 0 || a > ((size_t) -1) / b))
+        if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
                 return NULL;
 
         return malloc(a * b);
 }
 
 _alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t a, size_t b) {
-        if (_unlikely_(b == 0 || a > ((size_t) -1) / b))
+        if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
                 return NULL;
 
         return memdup(p, a * b);