emacs-28 f393d0d441: Fix regression leading to flickering tooltips when the mouse is moved

[Po Lu]

branch: emacs-28
commit f393d0d441c3746f98007ae54341870a296bf809
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Fix regression leading to flickering tooltips when the mouse is moved
    
    * lisp/tooltip.el (tooltip-show-help): Compare string with
    previous tooltip string ignoring properties.
---
 lisp/tooltip.el | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/lisp/tooltip.el b/lisp/tooltip.el
index 1840016d7c..d162884230 100644
--- a/lisp/tooltip.el
+++ b/lisp/tooltip.el
@@ -378,9 +378,12 @@ MSG is either a help string to display, or nil to cancel 
the display."
               ;; Cancel display.  This also cancels a delayed tip, if
               ;; there is one.
               (tooltip-hide))
-             ((equal-including-properties previous-help msg)
-              ;; Same help as before (but possibly the mouse has moved).
-              ;; Keep what we have.
+             ((equal previous-help msg)
+              ;; Same help as before (but possibly the mouse has
+              ;; moved or the text properties have changed).  Keep
+              ;; what we have.  If only text properties have changed,
+              ;; the tooltip won't be updated, but that shouldn't
+              ;; occur.
               )
              (t
               ;; A different help.  Remove a previous tooltip, and