Don't leak old allocation if realloc fails to enlarge it

In ftfuncs.c, since the buffer being reallocated is a function local
buffer, used to accumulate data for a single run of the function and
then freed at the end of the function, we just free the old buffer if
realloc fails.

In atom.c however, the ReverseMap is a static buffer, so we operate in
temporary variables until we know we're successful, then update the
static variables.  If we fail, we leave the old static variables in place,
since they contain data about previous atoms we should maintain, not lose.

Reported by cppcheck:
[lib/libXfont/src/FreeType/ftfuncs.c:2122]: (error) Common realloc mistake:
 'ranges' nulled but not freed upon failure
[lib/libXfont/src/util/atom.c:126]: (error) Common realloc mistake:
 'reverseMap' nulled but not freed upon failure

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

1 files changed, 12 insertions, 8 deletions

diff --git a/src/util/atom.c b/src/util/atom.c
index c47cb5c..37811f9 100644
--- a/src/util/atom.c
+++ b/src/util/atom.c
@@ -118,19 +118,23 @@ ResizeHashTable (void)
 static int
 ResizeReverseMap (void)
 {
-    int ret = TRUE;
+    AtomListPtr *newMap;
+    int newMapSize;
+
     if (reverseMapSize == 0)
-	reverseMapSize = 1000;
+	newMapSize = 1000;
     else
-	reverseMapSize *= 2;
-    reverseMap = realloc (reverseMap, reverseMapSize * sizeof (AtomListPtr));
-    if (!reverseMap) {
+	newMapSize = reverseMapSize * 2;
+    newMap = realloc (reverseMap, newMapSize * sizeof (AtomListPtr));
+    if (newMap == NULL) {
 	fprintf(stderr, "ResizeReverseMap(): Error: Couldn't reallocate"
 		" reverseMap (%ld)\n",
-		reverseMapSize * (unsigned long)sizeof(AtomListPtr));
-	ret = FALSE;
+		newMapSize * (unsigned long)sizeof(AtomListPtr));
+	return FALSE;
     }
-    return ret;
+    reverseMap = newMap;
+    reverseMapSize = newMapSize;
+    return TRUE;
 }
 
 static int