From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 11 Jul 2025 22:33:26 +0000 (-0700)
Subject: Fix (find-file "/dev/null")
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=dce99f6a9861a71bc8bc300195651be64c540485;p=emacs.git

Fix (find-file "/dev/null")

* lisp/files.el (find-file-noselect-1): When the file exists,
propagate any errors signaled by insert-file-contents,
instead of propagating them only when the file is unreadable.
This way, (find-file "/dev/null") gives a sensible diagnostic
"not a regular file" instead of the nonsense
"Maximum buffer size exceeded".

(cherry picked from commit b911029f96b14a03398198d5a849d6f4d0d1e071)
---

diff --git a/lisp/files.el b/lisp/files.el
index b335d8d9651..3885637ed58 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -2671,27 +2671,29 @@ Do you want to revisit the file normally now? "))
       (and (not rawfile)
 	   (set-buffer-multibyte t))
       (if rawfile
-	  (condition-case ()
+	  (condition-case err
 	      (let ((inhibit-read-only t)
                     (enable-local-variables nil))
 		(insert-file-contents-literally filename t))
 	    (file-error
-	     (when (and (file-exists-p filename)
-			(not (file-readable-p filename)))
+	     (when (file-exists-p filename)
 	       (kill-buffer buf)
-	       (signal 'file-error (list "File is not readable"
-					 filename)))
+	       (signal 'file-error
+		       (if (file-readable-p filename)
+			   (cdr err)
+			 (list "File is not readable" filename))))
 	     ;; Unconditionally set error
 	     (setq error t)))
-	(condition-case ()
+	(condition-case err
 	    (let ((inhibit-read-only t))
 	      (insert-file-contents filename t))
 	  (file-error
-	   (when (and (file-exists-p filename)
-		      (not (file-readable-p filename)))
+	   (when (file-exists-p filename)
 	     (kill-buffer buf)
-	     (signal 'file-error (list "File is not readable"
-				       filename)))
+	     (signal 'file-error
+		     (if (file-readable-p filename)
+			 (cdr err)
+		       (list "File is not readable" filename))))
 	   ;; Run find-file-not-found-functions until one returns non-nil.
 	   (or (run-hook-with-args-until-success 'find-file-not-found-functions)
 	       ;; If they fail too, set error.