emacs-30 b5543c54bf0: Fix NULL pointer dereferences in xpm_load_image

[Po Lu]

branch: emacs-30
commit b5543c54bf08c4fa4cae6b7f404a37a2aee60cdf
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Fix NULL pointer dereferences in xpm_load_image
    
    * src/image.c (x_destroy_x_image): Correct test condition.
    (xpm_load_image): Do not release image data if it is still to be
    created.
---
 src/image.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/image.c b/src/image.c
index 5aabb517f30..f869a95c15d 100644
--- a/src/image.c
+++ b/src/image.c
@@ -3886,7 +3886,7 @@ x_create_x_image_and_pixmap (struct frame *f, int width, 
int height, int depth,
 static void
 x_destroy_x_image (XImage *ximg)
 {
-  if (ximg)
+  if (ximg->data)
     {
       xfree (ximg->data);
       ximg->data = NULL;
@@ -6505,9 +6505,12 @@ xpm_load_image (struct frame *f,
 
  failure:
   image_error ("Invalid XPM3 file (%s)", img->spec);
-  image_destroy_x_image (ximg);
-  image_destroy_x_image (mask_img);
-  image_clear_image (f, img);
+  if (ximg)
+    {
+      image_destroy_x_image (ximg);
+      image_destroy_x_image (mask_img);
+      image_clear_image (f, img);
+    }
   return 0;
 
 #undef match