emacs-28 b9b78b2: Fix Help functions for clicks on tool bar and tab bar

[Eli Zaretskii]

branch: emacs-28
commit b9b78b263148d26ea585622e98e8e5ccd2602799
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Fix Help functions for clicks on tool bar and tab bar
    
    * lisp/mouse.el (mouse-minibuffer-check): Don't assume posn-window
    returns a window.  (Bug#5199)
---
 lisp/mouse.el | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lisp/mouse.el b/lisp/mouse.el
index bb47d04..bcb58d1 100644
--- a/lisp/mouse.el
+++ b/lisp/mouse.el
@@ -571,7 +571,8 @@ This is the keyboard interface to \\[context-menu-map]."
 
 (defun mouse-minibuffer-check (event)
   (let ((w (posn-window (event-start event))))
-    (and (window-minibuffer-p w)
+    (and (windowp w)
+         (window-minibuffer-p w)
         (not (minibuffer-window-active-p w))
         (user-error "Minibuffer window is not active")))
   ;; Give temporary modes such as isearch a chance to turn off.