bug#59122: 29.0.50; global-text-scale-adjust not working

[Gregory Heytings <gregory@heytings.org>]

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>
> Here's the result of 'M-x global-text-scale-adjust RET' and then typing 
> '-' repeatedly (in emacs -Q):
>

Thanks.  A call to redisplay was missing in the previous patch; the 
attached one should work.

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From fa0825822c3ef344a3c18d3466fc4ac1820f91f6 Mon Sep 17 00:00:00 2001
From: Gregory Heytings <gregory@heytings.org>
Date: Thu, 10 Nov 2022 16:58:06 +0000
Subject: [PATCH] Fix global face scaling bug due to rounding.

* lisp/face-remap.el (global-text-scale-adjust): Try again if the face
height did not actually change.
(global-text-scale-adjust--increment-factor): New internal variable.
Fixes bug#59122.
---
 lisp/face-remap.el | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/lisp/face-remap.el b/lisp/face-remap.el
index 432385587b..3c14085a63 100644
--- a/lisp/face-remap.el
+++ b/lisp/face-remap.el
@@ -461,6 +461,8 @@ global-text-scale-adjust-limits
 
 (defvar global-text-scale-adjust--default-height nil)
 
+(defvar global-text-scale-adjust--increment-factor 5)
+
 ;;;###autoload (define-key ctl-x-map [(control meta ?+)] 'global-text-scale-adjust)
 ;;;###autoload (define-key ctl-x-map [(control meta ?=)] 'global-text-scale-adjust)
 ;;;###autoload (define-key ctl-x-map [(control meta ?-)] 'global-text-scale-adjust)
@@ -499,16 +501,23 @@ global-text-scale-adjust
            (cur (face-attribute 'default :height))
            (inc
             (pcase key
-              (?- (* (- increment) 5))
+              (?- (* (- increment)
+                     global-text-scale-adjust--increment-factor))
               (?0 (- global-text-scale-adjust--default-height cur))
-              (_ (* increment 5))))
+              (_ (* increment
+                    global-text-scale-adjust--increment-factor))))
            (new (+ cur inc)))
       (when (< (car global-text-scale-adjust-limits)
                new
                (cdr global-text-scale-adjust-limits))
         (let ((frame-inhibit-implied-resize
                (not global-text-scale-adjust-resizes-frames)))
-          (set-face-attribute 'default nil :height new)))
+          (set-face-attribute 'default nil :height new)
+          (redisplay 'force)
+          (when (= cur (face-attribute 'default :height))
+            (setq global-text-scale-adjust--increment-factor
+                  (1+ global-text-scale-adjust--increment-factor))
+            (global-text-scale-adjust increment))))
       (when (characterp key)
         (set-transient-map
          (let ((map (make-sparse-keymap)))
-- 
2.35.1