Ken Thomases : libwine: Fix a potential write through a null pointer. ( Clang).

[Alexandre Julliard]

Module: wine
Branch: stable
Commit: acc524066b5a6cce6bbef354f0594f105a8803ed
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=acc524066b5a6cce6bbef354f0594f105a8803ed

Author: Ken Thomases <ken at codeweavers.com>
Date:   Sun Oct 20 23:55:47 2013 -0500

libwine: Fix a potential write through a null pointer. (Clang).

(cherry picked from commit e577e4b3e646b0a296ce9bbd73f728cc3f92c20e)

---

 libs/wine/loader.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/libs/wine/loader.c b/libs/wine/loader.c
index 4e78116..42cd6f5 100644
--- a/libs/wine/loader.c
+++ b/libs/wine/loader.c
@@ -880,10 +880,13 @@ void *wine_dlopen( const char *filename, int flag, char *error, size_t errorsize
     {
         if (pread( fd, magic, 2, 0 ) == 2 && magic[0] == 'M' && magic[1] == 'Z')
         {
-            static const char msg[] = "MZ format";
-            size_t len = min( errorsize, sizeof(msg) );
-            memcpy( error, msg, len );
-            error[len - 1] = 0;
+            if (error && errorsize)
+            {
+                static const char msg[] = "MZ format";
+                size_t len = min( errorsize, sizeof(msg) );
+                memcpy( error, msg, len );
+                error[len - 1] = 0;
+            }
             close( fd );
             return NULL;
         }