Bug#1016081: elpa-magit: Magit saves wrong buffers for remote repository

[Toby Speight <T.M.Speight.90@cantab.net>]

Package: elpa-magit
Version: 3.3.0-1
Severity: normal
Tags: patch
X-Debbugs-Cc: Toby Speight <T.M.Speight.90@cantab.net>
File: /usr/share/emacs/site-lisp/elpa-src/magit-3.3.0/magit-mode.el

When working remotely over SSH, I find that Magit offers to save only
local files, rather than the ones on the host where Git is running.

The problem stems from `magit-save-repository-buffers', which begins
around line 1208:

/--------
|   (when-let ((topdir (magit-rev-parse-safe "--show-toplevel")))
|     (let ((remote (file-remote-p topdir))
\--------

`topdir' is the output from "git rev-parse --show-toplevel", which is a
pathname _on the remote machine_, without any adornment.  So `remote' is
always nil, even for such a repository.

I get the desired behavour if I make the following changes, which could
be a candidate for upstream:

--- /usr/share/emacs/site-lisp/elpa-src/magit-3.3.0/magit-mode.el	2022-07-26 08:58:43.534569844 +0100
+++ /usr/share/emacs/site-lisp/elpa-src/magit-3.3.0/magit-mode.el	2022-07-26 08:58:43.534569844 +0100
@@ -1206,7 +1206,7 @@
 argument (the prefix) non-nil means save all with no questions."
   (interactive "P")
   (when-let ((topdir (magit-rev-parse-safe "--show-toplevel")))
-    (let ((remote (file-remote-p topdir))
+    (let ((remote (file-remote-p default-directory))
           (save-some-buffers-action-alist
            `((?Y (lambda (buffer)
                    (with-current-buffer buffer
@@ -1229,7 +1229,7 @@
                   ;; therefore has to come after the above to avoid
                   ;; unnecessarily waiting for unrelated hosts.
                   (file-exists-p (file-name-directory buffer-file-name))
-                  (string-prefix-p topdir (file-truename buffer-file-name))
+                  (string-prefix-p topdir (file-local-name (file-truename buffer-file-name)))
                   (equal (magit-rev-parse-safe "--show-toplevel")
                          topdir)))))))
 

-- System Information:
Debian Release: bookworm/sid
  APT prefers testing
  APT policy: (900, 'testing'), (400, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.10.0-6-amd64 (SMP w/8 CPU threads)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages elpa-magit depends on:
ii  dh-elpa-helper      2.0.10
ii  elpa-dash           2.19.1+dfsg-1
ii  elpa-git-commit     3.3.0-1
ii  elpa-magit-section  3.3.0-1
ii  elpa-transient      0.3.7-1
ii  elpa-with-editor    3.0.5-1
ii  emacsen-common      3.0.4
ii  git                 1:2.35.1-1

elpa-magit recommends no packages.

elpa-magit suggests no packages.

-- no debconf information