feat(magit): introduce +magit-auto-revert option

Provides more control over our auto-reverting feature, and changes its
behavior to only target non-remote buffers by default, because reverting
remote buffers could be tremendously slow.

This could be later improved to treat TRAMP buffers with local
methods (like sudo) as local buffers.

Fix: #8354

modules/tools/magit/autoload.el

@@ -98,6 +98,17 @@ window that already exists in that direction. It will split otherwise."
 
 (defvar +magit--stale-p nil)
 
+(defun +magit--revertable-buffer-p (buffer)
+  (when (buffer-live-p buffer)
+    (pcase +magit-auto-revert
+      (`t t)
+      (`local
+       (not (file-remote-p
+             (or (buffer-file-name buffer)
+                 (buffer-local-value 'default-directory buffer)))))
+      ((pred functionp)
+       (funcall +magit-auto-revert buffer)))))
+
 (defun +magit--revert-buffer (buffer)
   (with-current-buffer buffer
     (kill-local-variable '+magit--stale-p)
@@ -116,7 +127,7 @@ Stale buffers are reverted when they are switched to, assuming they haven't been
 modified."
   (let ((visible-buffers (doom-visible-buffers nil t)))
     (dolist (buffer (buffer-list))
-      (when (buffer-live-p buffer)
+      (when (+magit--revertable-buffer-p buffer)
         (if (memq buffer visible-buffers)
             (progn
               (+magit--revert-buffer buffer)

modules/tools/magit/config.el

@@ -12,6 +12,28 @@ left and right fringe.
 
 Only has an effect in GUI Emacs.")
 
+(defvar +magit-auto-revert 'local
+  "If non-nil, revert associated buffers after Git operations with side-effects.
+
+These buffers are auto-reverted immediately if they're visible or reverted next
+time they're switched to. This is intended to be a much more efficient
+replacement for `magit-auto-revert-mode' and `global-auto-revert-mode', and
+should not be used together with them! Set this to `nil' if you plan to use the
+above.
+
+Accepts one of three values OR a predicate function:
+
+t
+  Revert any associated buffers.
+local
+  Same as `t', except remote (TRAMP) buffers are ignored.
+nil
+  Don't do any auto-reverting at all.
+FUNCTION
+  If given a function, it will be passed a buffer associated with the current
+  Magit session and must return non-nil to signal this is buffer is safe to
+  revert (now or later, when switched to).")
+
 
 ;;
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