From b385fd0b880059f74d5c1409a08a9e1292b86e70 Mon Sep 17 00:00:00 2001
From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Sun, 10 Apr 2022 13:48:46 +0200
Subject: [PATCH] Revert "Make shell-resync-dirs handle whitespace in directory
 names"

This reverts commit 90e65c826fab2092ad2099d7763538194c93e021.

This change led to hangs (bug#54776).

Do not merge to master; it has been fixed in a more encompassing way there.
---
 lisp/shell.el | 54 ++++++++++++++++++---------------------------------
 1 file changed, 19 insertions(+), 35 deletions(-)

diff --git a/lisp/shell.el b/lisp/shell.el
index c9def1bb3f3..f0115b90a50 100644
--- a/lisp/shell.el
+++ b/lisp/shell.el
@@ -1060,41 +1060,25 @@ command again."
 	  (accept-process-output proc)
 	  (goto-char pt)))
       (goto-char pmark) (delete-char 1) ; remove the extra newline
-      ;; That's the dirlist.  Grab it & parse it.
-      (let* ((dls (buffer-substring-no-properties
-                   (match-beginning 0) (1- (match-end 0))))
-             (dlsl nil)
-             (pos 0)
-             (ds nil))
-        ;; Split the dirlist into whitespace and non-whitespace chunks.
-        ;; dlsl will be a reversed list of tokens.
-        (while (string-match "\\(\\S-+\\|\\s-+\\)" dls pos)
-          (push (match-string 1 dls) dlsl)
-          (setq pos (match-end 1)))
-
-        ;; Prepend trailing entries until they form an existing directory,
-        ;; whitespace and all.  Discard the next whitespace and repeat.
-        (while dlsl
-          (let ((newelt "")
-                tem1 tem2)
-            (while newelt
-              ;; We need tem1 because we don't want to prepend
-              ;; `comint-file-name-prefix' repeatedly into newelt via tem2.
-              (setq tem1 (pop dlsl)
-                    tem2 (concat comint-file-name-prefix tem1 newelt))
-              (cond ((file-directory-p tem2)
-                     (push tem2 ds)
-                     (when (string= " " (car dlsl))
-                       (pop dlsl))
-                     (setq newelt nil))
-                    (t
-                     (setq newelt (concat tem1 newelt)))))))
-
-        (with-demoted-errors "Couldn't cd: %s"
-          (shell-cd (car ds))
-          (setq shell-dirstack (cdr ds)
-                shell-last-dir (car shell-dirstack))
-          (shell-dirstack-message))))
+      ;; That's the dirlist. grab it & parse it.
+      (let* ((dl (buffer-substring (match-beginning 2) (1- (match-end 2))))
+	     (dl-len (length dl))
+	     (ds '())			; new dir stack
+	     (i 0))
+	(while (< i dl-len)
+	  ;; regexp = optional whitespace, (non-whitespace), optional whitespace
+	  (string-match "\\s *\\(\\S +\\)\\s *" dl i) ; pick off next dir
+	  (setq ds (cons (concat comint-file-name-prefix
+				 (substring dl (match-beginning 1)
+					    (match-end 1)))
+			 ds))
+	  (setq i (match-end 0)))
+	(let ((ds (nreverse ds)))
+	  (with-demoted-errors "Couldn't cd: %s"
+	    (shell-cd (car ds))
+	    (setq shell-dirstack (cdr ds)
+		  shell-last-dir (car shell-dirstack))
+	    (shell-dirstack-message)))))
     (if started-at-pmark (goto-char (marker-position pmark)))))
 
 ;; For your typing convenience:
-- 
2.39.2