From 11ce194dcf060782f1457c77a44f791389ed32f0 Mon Sep 17 00:00:00 2001
From: Ihor Radchenko <yantar92@posteo.net>
Date: Fri, 4 Aug 2023 10:53:17 +0300
Subject: [PATCH] org-string-width: Fix Emacs <29 compatibility

* lisp/org-compat.el (org-buffer-text-pixel-width): New function using
`buffer-text-pixel-size' in Emacs >=29 and falling back to
`window-text-pixel-size' in older Emacs.
* lisp/org-macs.el (org-string-width): Use the new function.
---
 lisp/org-compat.el | 21 +++++++++++++++++++++
 lisp/org-macs.el   |  4 ++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/lisp/org-compat.el b/lisp/org-compat.el
index bbda04a15..8d4b98282 100644
--- a/lisp/org-compat.el
+++ b/lisp/org-compat.el
@@ -137,6 +137,27 @@ Upper-case and lower-case letters are treated as equal.
 Unibyte strings are converted to multibyte for comparison."
     (eq t (compare-strings string1 0 nil string2 0 nil t))))
 
+(defun org-buffer-text-pixel-width ()
+  "Return pixel width of text in current buffer.
+This function uses `buffer-text-pixel-size', when available, and falls
+back to `window-text-pixel-size' otherwise."
+  (if (fboundp 'buffer-text-pixel-size)
+      (car (buffer-text-pixel-size nil nil t))
+    (if (get-buffer-window (current-buffer))
+        (car (window-text-pixel-size
+              nil (point-min) (point-max)))
+      (let ((dedicatedp (window-dedicated-p))
+            (oldbuffer (window-buffer)))
+        (unwind-protect
+            (progn
+              ;; Do not throw error in dedicated windows.
+              (set-window-dedicated-p nil nil)
+              (set-window-buffer nil (current-buffer))
+              (car (window-text-pixel-size
+                    nil (point-min) (point-max))))
+          (set-window-buffer nil oldbuffer)
+          (set-window-dedicated-p nil dedicatedp))))))
+
 
 ;;; Emacs < 28.1 compatibility
 
diff --git a/lisp/org-macs.el b/lisp/org-macs.el
index b8c6c0132..e102f01c3 100644
--- a/lisp/org-macs.el
+++ b/lisp/org-macs.el
@@ -1136,11 +1136,11 @@ Return width in pixels when PIXELS is non-nil."
           (with-silent-modifications
             (erase-buffer)
             (insert string)
-            (setq pixel-width (car (buffer-text-pixel-size nil nil t)))
+            (setq pixel-width (org-buffer-text-pixel-width))
             (unless pixels
               (erase-buffer)
               (insert "a")
-              (setq symbol-width (car (buffer-text-pixel-size nil nil t)))))
+              (setq symbol-width (org-buffer-text-pixel-width))))
           (if pixels
               pixel-width
             (/ pixel-width symbol-width)))))))