In
mesa/src/gallium/auxiliary/hud/hud_context.c
we find the following code

      case ',':
         env++;
         y += height + hud->font.glyph_height * (pane->num_graphs + 2);

         if (pane && pane->num_graphs) {
            LIST_ADDTAIL(&pane->head, &hud->pane_list);
            pane = NULL;
         }
         break;

pane is checked for being NULL. So obviously we expect NULL as possible value.
But we use pane->num_graphs before the check. This is possibly a NULL-pointer
dereference.

The problem was indicated by cppcheck
http://cppcheck.sourceforge.net/

Best regards

Heinrich Schuchardt