Re: Fwd: [PATCH] Don’t run smerge multiple times

[Stefan Monnier]

Matthew Bauer [2020-03-17 20:07:25] wrote:

>> This sounds like a problem in itself.
>> Or is it really because the file gets modified multiple times?
> I think it is caused by each edit.

I see, thanks.

> At least the symptom is that after so much idle time,
> vc-git-find-file-hook gets run.  Now that I'm looking for it, I don't
> actually see vc-git-find-file-hook is added to any hooks, so something
> seems off.  It may be some kind of interaction with Magit that sets
> this up.

`vc-git-find-file-hook` is run by `vc-refresh-state`:

    [...]
    (vc-call-backend backend 'find-file-hook)
    [...]

and `vc-refresh-state` is on `find-file-hook`.
This is true regardless of Magit.

>>> Related to
>>> https://lists.gnu.org/archive/html/emacs-devel/2015-10/msg02201.html
>
>> That patch was never installed.  Has that problem been
>> fixed/circumvented some other way?
>
> It looks like it was fixed in
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=21559 in a different way.

Good, thanks.  I think the original patch's intent was good, tho.
I installed the patch below into `master`.


        Stefan


diff --git a/lisp/vc/smerge-mode.el b/lisp/vc/smerge-mode.el
index 85868b91ec..d0a83fd7c4 100644
--- a/lisp/vc/smerge-mode.el
+++ b/lisp/vc/smerge-mode.el
@@ -1429,15 +1429,16 @@ smerge-mode
     (smerge-remove-props (point-min) (point-max))))
 
 ;;;###autoload
-(defun smerge-start-session ()
+(defun smerge-start-session (&optional interactively)
   "Turn on `smerge-mode' and move point to first conflict marker.
 If no conflict maker is found, turn off `smerge-mode'."
-  (interactive)
-  (smerge-mode 1)
-  (condition-case nil
-      (unless (looking-at smerge-begin-re)
-        (smerge-next))
-    (error (smerge-auto-leave))))
+  (interactive "p")
+  (when (or (null smerge-mode) interactively)
+    (smerge-mode 1)
+    (condition-case nil
+        (unless (looking-at smerge-begin-re)
+          (smerge-next))
+      (error (smerge-auto-leave)))))
 
 (defcustom smerge-change-buffer-confirm t
   "If non-nil, request confirmation before moving to another buffer."