[PATCH 6/8] Avoid memory leak on realloc failure in localRegisterFreeBoxCallback

[Alan Coopersmith]

Also avoids leaving invalid pointers in structures if realloc had to
move them elsewhere to make them larger.

Found by parfait 1.1 code analyzer:
   Memory leak of pointer 'newCallbacks' allocated with realloc(((char*)offman->FreeBoxesUpdateCallback), (8 * (offman->NumCallbacks + 1)))
        at line 328 of hw/xfree86/common/xf86fbman.c in function 'localRegisterFreeBoxCallback'.
          'newCallbacks' allocated at line 320 with realloc(((char*)offman->FreeBoxesUpdateCallback), (8 * (offman->NumCallbacks + 1))).
          newCallbacks leaks when newCallbacks != NULL at line 327.
   Memory leak of pointer 'newPrivates' allocated with realloc(((char*)offman->devPrivates), (8 * (offman->NumCallbacks + 1)))
        at line 328 of hw/xfree86/common/xf86fbman.c in function 'localRegisterFreeBoxCallback'.
          'newPrivates' allocated at line 324 with realloc(((char*)offman->devPrivates), (8 * (offman->NumCallbacks + 1))).
          newPrivates leaks when newCallbacks == NULL at line 327.

Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>
---
 hw/xfree86/common/xf86fbman.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/hw/xfree86/common/xf86fbman.c b/hw/xfree86/common/xf86fbman.c
index c2e7bab..4da6af2 100644
--- a/hw/xfree86/common/xf86fbman.c
+++ b/hw/xfree86/common/xf86fbman.c
@@ -320,15 +320,17 @@ localRegisterFreeBoxCallback(ScreenPtr pScreen,
     newCallbacks = realloc(offman->FreeBoxesUpdateCallback,
                            sizeof(FreeBoxCallbackProcPtr) *
                            (offman->NumCallbacks + 1));
+    if (!newCallbacks)
+        return FALSE;
+    else
+        offman->FreeBoxesUpdateCallback = newCallbacks;
 
     newPrivates = realloc(offman->devPrivates,
                           sizeof(DevUnion) * (offman->NumCallbacks + 1));
-
-    if (!newCallbacks || !newPrivates)
+    if (!newPrivates)
         return FALSE;
-
-    offman->FreeBoxesUpdateCallback = newCallbacks;
-    offman->devPrivates = newPrivates;
+    else
+        offman->devPrivates = newPrivates;
 
     offman->FreeBoxesUpdateCallback[offman->NumCallbacks] = FreeBoxCallback;
     offman->devPrivates[offman->NumCallbacks].ptr = devPriv;
-- 
1.7.9.2