emacs-27 3711339: Fix crash in ns_mouse_position (bug#45541)

[Alan Third]

branch: emacs-27
commit 3711339f92be0c50633aefae991d8fa4a135fe33
Author: Alan Third <alan@idiocy.org>
Commit: Alan Third <alan@idiocy.org>

    Fix crash in ns_mouse_position (bug#45541)
    
    * src/nsterm.m (ns_mouse_position): Explicitly initialize f to NULL.
    
    ; Do not merge to master
---
 src/nsterm.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/nsterm.m b/src/nsterm.m
index b75c6c7..b8658a0 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -2480,7 +2480,7 @@ ns_mouse_position (struct frame **fp, int insist, 
Lisp_Object *bar_window,
   id view;
   NSPoint view_position;
   Lisp_Object frame, tail;
-  struct frame *f;
+  struct frame *f = NULL;
   struct ns_display_info *dpyinfo;
 
   NSTRACE ("ns_mouse_position");