From 98cfa9bf6d9ec23573365031b3734fb9c2965dd5 Mon Sep 17 00:00:00 2001
From: Sean Whitton <spwhitton@spwhitton.name>
Date: Fri, 4 Oct 2024 08:19:40 +0800
Subject: [PATCH] icomplete-completions: Compute prospects-len more efficiently

* lisp/icomplete.el (icomplete-completions): Avoid calling
string-width on the entire buffer-string when computing
prospects-len (bug#72826).
---
 lisp/icomplete.el | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lisp/icomplete.el b/lisp/icomplete.el
index 2ea5e36fa88..9497b46c6cf 100644
--- a/lisp/icomplete.el
+++ b/lisp/icomplete.el
@@ -1007,7 +1007,12 @@ icomplete-completions
                                   (or determ (concat open-bracket close-bracket)))
                                  (string-width icomplete-separator)
                                  (+ 2 (string-width ellipsis)) ;; take {…} into account
-                                 (string-width (buffer-string))))
+                                 (string-width
+                                  (buffer-substring
+                                   (save-excursion
+                                     (goto-char (icomplete--field-beg))
+                                     (pos-bol))
+                                   (icomplete--field-end)))))
                (prospects-max
                 ;; Max total length to use, including the minibuffer content.
                 (* (+ icomplete-prospects-height
-- 
2.45.2