master a67b1f1944: Make sure widget buttons always have a left box line

[Po Lu]

branch: master
commit a67b1f1944262f41e58c87f09d28858725aa5ca9
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Make sure widget buttons always have a left box line
    
    * lisp/wid-edit.el (widget-specify-button): Add an invisible
    before-string to the button overlay.  (bug#51550)
---
 lisp/wid-edit.el | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lisp/wid-edit.el b/lisp/wid-edit.el
index a53add7d08..22f3d29908 100644
--- a/lisp/wid-edit.el
+++ b/lisp/wid-edit.el
@@ -437,8 +437,9 @@ the :notify function can't know the new value.")
        (follow-link (widget-get widget :follow-link))
        (help-echo (widget-get widget :help-echo)))
     (widget-put widget :button-overlay overlay)
-    (if (functionp help-echo)
+    (when (functionp help-echo)
       (setq help-echo 'widget-mouse-help))
+    (overlay-put overlay 'before-string #(" " 0 1 (invisible t)))
     (overlay-put overlay 'button widget)
     (overlay-put overlay 'keymap (widget-get widget :keymap))
     (overlay-put overlay 'evaporate t)