XPM loader: Add missing pixels (malformed xpm)

If there are not enough pixels in the image data just fill in the first
color.

This way we will proceed without uninitialized pixel data avoiding
valgrind complaints.

src/modules/loaders/loader_xpm.c

@@ -431,6 +431,13 @@ load(ImlibImage * im, ImlibProgressFunction progress, char progress_granularity,
            done = 1;
      }
 
+   for (; count < pixels; count++)
+     {
+        /* Fill in missing pixels
+         * (avoid working with uninitialized data in bad xpms) */
+        im->data[count] = cmap[0].pixel;
+     }
+
    if (transp >= 0)
      {
         SET_FLAG(im->flags, F_HAS_ALPHA);