shadowfile.el uses eqhemeral buffer names now

* etc/NEWS: shadowfile.el uses eqhemeral buffer names now.

* lisp/shadowfile.el (shadow-find-file-noselect): New function.
(shadow-read-files, shadow-write-info-file)
(shadow-write-todo-file): Use it.

2 files changed, 17 insertions, 4 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 7cc2cca65f8..a9d5329bce8 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -3339,6 +3339,11 @@ If an active region exists, the commands 'hi-lock-line-face-buffer' and
 'hi-lock-face-phrase-buffer' now use its contents as their default
 value.  Previously, only 'hi-lock-face-buffer' supported this.
 
+** Shadowfile
+
+*** 'shadow-info-buffer' and 'shadow-todo-buffer' use eqhemeral buffer names now.
+This excludes the buffers from save buffer predicates.
+
 
 * New Modes and Packages in Emacs 31.1
 
diff --git a/lisp/shadowfile.el b/lisp/shadowfile.el
index 7fd7dc94ad0..7f4f5b56a1f 100644
--- a/lisp/shadowfile.el
+++ b/lisp/shadowfile.el
@@ -667,6 +667,12 @@ PAIR must be `eq' to one of the elements of that list."
   (setq shadow-files-to-copy
         (cl-remove-if (lambda (s) (eq s pair)) shadow-files-to-copy)))
 
+(defun shadow-find-file-noselect (filename &optional nowarn)
+  "Like `find-file-noselect', but make buffer name ephemeral."
+  (with-current-buffer (find-file-noselect filename nowarn)
+    (rename-buffer (format " *%s*" (buffer-name)))
+    (current-buffer)))
+
 (defun shadow-read-files ()
   "Visit and load `shadow-info-file' and `shadow-todo-file'.
 Thus restores shadowfile's state from your last Emacs session.
@@ -682,7 +688,7 @@ Return t unless files were locked; then return nil."
     (save-current-buffer
       (when shadow-info-file
         (set-buffer (setq shadow-info-buffer
-                          (find-file-noselect shadow-info-file 'nowarn)))
+                          (shadow-find-file-noselect shadow-info-file 'nowarn)))
         (lisp-data-mode)
         (setq-local lexical-binding t)
         (when (and (not (buffer-modified-p))
@@ -695,7 +701,7 @@ Return t unless files were locked; then return nil."
         (eval-buffer))
       (when shadow-todo-file
         (set-buffer (setq shadow-todo-buffer
-                          (find-file-noselect shadow-todo-file 'nowarn)))
+                          (shadow-find-file-noselect shadow-todo-file 'nowarn)))
         (lisp-data-mode)
         (setq-local lexical-binding t)
         (when (and (not (buffer-modified-p))
@@ -717,7 +723,8 @@ defined, the old hashtable info is invalid."
   (if shadow-info-file
       (save-current-buffer
         (if (not shadow-info-buffer)
-            (setq shadow-info-buffer (find-file-noselect shadow-info-file)))
+            (setq shadow-info-buffer
+                  (shadow-find-file-noselect shadow-info-file)))
         (set-buffer shadow-info-buffer)
         (setq buffer-read-only nil)
         (delete-region (point-min) (point-max))
@@ -730,7 +737,8 @@ defined, the old hashtable info is invalid."
 With non-nil argument also saves the buffer."
   (save-excursion
     (if (not shadow-todo-buffer)
-        (setq shadow-todo-buffer (find-file-noselect shadow-todo-file)))
+        (setq shadow-todo-buffer
+              (shadow-find-file-noselect shadow-todo-file)))
     (set-buffer shadow-todo-buffer)
     (setq buffer-read-only nil)
     (delete-region (point-min) (point-max))