From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Wed, 24 Nov 2021 07:27:22 +0000 (+0100)
Subject: Fix string-glyph-split infloop
X-Git-Tag: emacs-29.0.90~2852^2~81^2
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=3a2eee6f7439866ac51d0d4c7b43f7f9f6f88fe2;p=emacs.git

Fix string-glyph-split infloop

* lisp/emacs-lisp/subr-x.el (string-glyph-split): Fix infloop when
applied to (string-glyph-split "✈️🌍") (bug#52067).
---

diff --git a/lisp/emacs-lisp/subr-x.el b/lisp/emacs-lisp/subr-x.el
index b2dae564c2b..95254b946e5 100644
--- a/lisp/emacs-lisp/subr-x.el
+++ b/lisp/emacs-lisp/subr-x.el
@@ -456,7 +456,12 @@ This takes into account combining characters and grapheme clusters."
         (start 0)
         comp)
     (while (< start (length string))
-      (if (setq comp (find-composition-internal start nil string nil))
+      (if (setq comp (find-composition-internal
+                      start
+                      ;; Don't search backward in the string for the
+                      ;; start of the composition.
+                      (min (length string) (1+ start))
+                      string nil))
           (progn
             (push (substring string (car comp) (cadr comp)) result)
             (setq start (cadr comp)))