glamor: zero num_modifiers from the start

The caller may ignore the return value (will be addressed with later
commit) so simply zero the count from the get-go. We're pretty much do
so, in all cases but one :-\

Fixes: cef12efc15c ("glamor: Implement GetSupportedModifiers")
Cc: Louis-Francis Ratté-Boulianne <lfrb@collabora.com>
Cc: Daniel Stone <daniels@collabora.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>

1 files changed, 6 insertions, 10 deletions

diff --git a/glamor/glamor_egl.c b/glamor/glamor_egl.c
index 3d102ad22..7050bd001 100644
--- a/glamor/glamor_egl.c
+++ b/glamor/glamor_egl.c
@@ -640,31 +640,27 @@ glamor_get_modifiers(ScreenPtr screen, CARD32 format,
     struct glamor_egl_screen_private *glamor_egl;
     EGLint num;
 
+    /* Explicitly zero the count as the caller may ignore the return value */
+    *num_modifiers = 0;
+
     glamor_egl = glamor_egl_get_screen_private(xf86ScreenToScrn(screen));
 
     if (!glamor_egl->dmabuf_capable)
         return FALSE;
 
     if (!eglQueryDmaBufModifiersEXT(glamor_egl->display, format, 0, NULL,
-                                    NULL, &num)) {
-        *num_modifiers = 0;
+                                    NULL, &num))
         return FALSE;
-    }
 
-    if (num == 0) {
-        *num_modifiers = 0;
+    if (num == 0)
         return TRUE;
-    }
 
     *modifiers = calloc(num, sizeof(uint64_t));
-    if (*modifiers == NULL) {
-        *num_modifiers = 0;
+    if (*modifiers == NULL)
         return FALSE;
-    }
 
     if (!eglQueryDmaBufModifiersEXT(glamor_egl->display, format, num,
                                     (EGLuint64KHR *) *modifiers, NULL, &num)) {
-        *num_modifiers = 0;
         free(*modifiers);
         return FALSE;
     }