master 2b34304: ; Add comment for a recent change

[Eli Zaretskii]

branch: master
commit 2b34304ad431e4a9f1c655f93862e24ccc55c8d6
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    ; Add comment for a recent change
    
    * lisp/faces.el (help-key-binding): Comment on the reason for a
    recent change.
---
 lisp/faces.el | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lisp/faces.el b/lisp/faces.el
index ec650e3..573428f 100644
--- a/lisp/faces.el
+++ b/lisp/faces.el
@@ -2818,6 +2818,9 @@ Note: Other faces cannot inherit from the cursor face."
 (defface help-key-binding
   '((((class color) (min-colors 88) (background light))
      :background "grey92" :foreground "DarkBlue"
+     ;; We use negative thickness of the horizontal box border line to
+     ;; avoid enlarging the height of the echo-area display, which
+     ;; would then move the mode line a few pixels up.
      :box (:line-width (1 . -1) :color "grey80"))
     (((class color) (min-colors 88) (background dark))
      :background "grey23" :foreground "LightBlue"