* bug#18535: tramp alters `vc-handled-backends'
@ 2014-09-23 10:53 Emilio Lopes
2014-09-23 15:37 ` Stefan Monnier
0 siblings, 1 reply; 4+ messages in thread
From: Emilio Lopes @ 2014-09-23 10:53 UTC (permalink / raw)
To: 18535
`tramp-sh-handle-vc-registered' can permanently alter the value of
`vc-handled-backends' causing Emacs to stop recognizing version
controlled files as such. This happened to me a couple of times after
having pressed `C-g' while some `tramp' operation was apparently
hanging.
Here is a patch:
=== modified file 'lisp/ChangeLog'
--- lisp/ChangeLog 2014-09-16 13:36:04 +0000
+++ lisp/ChangeLog 2014-09-23 09:27:10 +0000
@@ -1,4 +1,9 @@
+2014-09-23 Emilio C. Lopes <eclig@gmx.net>
+
+ * net/tramp-sh.el (tramp-sh-handle-vc-registered): use `unwind-protect'
+ to avoid altering `vc-handled-backends' permanently.
+
2014-09-22 Kan-Ru Chen <kanru@kanru.info>
* window.el (fit-window-to-buffer): When counting buffer width,
count the whole visible buffer. Correctly convert the body-height
=== modified file 'lisp/net/tramp-sh.el'
--- lisp/net/tramp-sh.el 2014-09-08 15:52:04 +0000
+++ lisp/net/tramp-sh.el 2014-09-23 09:27:10 +0000
@@ -3456,30 +3456,33 @@
;; calls shall be answered from the file cache. We unset
;; `process-file-side-effects' and `remote-file-name-inhibit-cache'
;; in order to keep the cache.
- (let ((vc-handled-backends vc-handled-backends)
+ (let ((vc-handled-backends-saved vc-handled-backends)
remote-file-name-inhibit-cache process-file-side-effects)
;; Reduce `vc-handled-backends' in order to minimize process calls.
- (when (and (memq 'Bzr vc-handled-backends)
- (boundp 'vc-bzr-program)
- (not (with-tramp-connection-property v vc-bzr-program
- (tramp-find-executable
- v vc-bzr-program (tramp-get-remote-path v)))))
- (setq vc-handled-backends (delq 'Bzr vc-handled-backends)))
- (when (and (memq 'Git vc-handled-backends)
- (boundp 'vc-git-program)
- (not (with-tramp-connection-property v vc-git-program
- (tramp-find-executable
- v vc-git-program (tramp-get-remote-path v)))))
- (setq vc-handled-backends (delq 'Git vc-handled-backends)))
- (when (and (memq 'Hg vc-handled-backends)
- (boundp 'vc-hg-program)
- (not (with-tramp-connection-property v vc-hg-program
- (tramp-find-executable
- v vc-hg-program (tramp-get-remote-path v)))))
- (setq vc-handled-backends (delq 'Hg vc-handled-backends)))
- ;; Run.
- (ignore-errors
- (tramp-run-real-handler 'vc-registered (list file))))))))
+ (unwind-protect
+ (progn
+ (when (and (memq 'Bzr vc-handled-backends)
+ (boundp 'vc-bzr-program)
+ (not (with-tramp-connection-property v
vc-bzr-program
+ (tramp-find-executable
+ v vc-bzr-program
(tramp-get-remote-path v)))))
+ (setq vc-handled-backends (delq 'Bzr vc-handled-backends)))
+ (when (and (memq 'Git vc-handled-backends)
+ (boundp 'vc-git-program)
+ (not (with-tramp-connection-property v
vc-git-program
+ (tramp-find-executable
+ v vc-git-program
(tramp-get-remote-path v)))))
+ (setq vc-handled-backends (delq 'Git vc-handled-backends)))
+ (when (and (memq 'Hg vc-handled-backends)
+ (boundp 'vc-hg-program)
+ (not (with-tramp-connection-property v vc-hg-program
+ (tramp-find-executable
+ v vc-hg-program
(tramp-get-remote-path v)))))
+ (setq vc-handled-backends (delq 'Hg vc-handled-backends)))
+ ;; Run.
+ (ignore-errors
+ (tramp-run-real-handler 'vc-registered (list file))))
+ (setq vc-handled-backends vc-handled-backends-saved)))))))
;;;###tramp-autoload
(defun tramp-sh-file-name-handler (operation &rest args)
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#18535: tramp alters `vc-handled-backends'
2014-09-23 10:53 bug#18535: tramp alters `vc-handled-backends' Emilio Lopes
@ 2014-09-23 15:37 ` Stefan Monnier
2014-09-25 7:10 ` Emilio Lopes
0 siblings, 1 reply; 4+ messages in thread
From: Stefan Monnier @ 2014-09-23 15:37 UTC (permalink / raw)
To: Emilio Lopes; +Cc: 18535
> `tramp-sh-handle-vc-registered' can permanently alter the value of
> `vc-handled-backends' causing Emacs to stop recognizing version
> controlled files as such. This happened to me a couple of times after
> having pressed `C-g' while some `tramp' operation was apparently
> hanging.
The current code uses a `let' binding, which uses the same mechanism as
unwind-protect, so I don't think that's the source of a the problem.
The `delq' look dangerous on the other hand. Shouldn't these be
`remq' instead?
Stefan
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#18535: tramp alters `vc-handled-backends'
2014-09-23 15:37 ` Stefan Monnier
@ 2014-09-25 7:10 ` Emilio Lopes
2014-09-25 13:07 ` Stefan Monnier
0 siblings, 1 reply; 4+ messages in thread
From: Emilio Lopes @ 2014-09-25 7:10 UTC (permalink / raw)
To: Stefan Monnier; +Cc: 18535
2014-09-23 17:37 GMT+02:00 Stefan Monnier <monnier@iro.umontreal.ca>:
>> `tramp-sh-handle-vc-registered' can permanently alter the value of
>> `vc-handled-backends' causing Emacs to stop recognizing version
>> controlled files as such. This happened to me a couple of times after
>> having pressed `C-g' while some `tramp' operation was apparently
>> hanging.
>
> The current code uses a `let' binding, which uses the same mechanism as
> unwind-protect, so I don't think that's the source of a the problem.
Is this common behavior in Lisps? I could not find any reference to
this in the Elisp manual.
Anyway, thanks for point this out!
> The `delq' look dangerous on the other hand. Shouldn't these be
> `remq' instead?
yes, this seems to solve the problem.
=== modified file 'lisp/net/tramp-sh.el'
--- lisp/net/tramp-sh.el 2014-09-08 15:52:04 +0000
+++ lisp/net/tramp-sh.el 2014-09-25 07:07:25 +0000
@@ -3464,19 +3464,19 @@
(not (with-tramp-connection-property v vc-bzr-program
(tramp-find-executable
v vc-bzr-program (tramp-get-remote-path v)))))
- (setq vc-handled-backends (delq 'Bzr vc-handled-backends)))
+ (setq vc-handled-backends (remq 'Bzr vc-handled-backends)))
(when (and (memq 'Git vc-handled-backends)
(boundp 'vc-git-program)
(not (with-tramp-connection-property v vc-git-program
(tramp-find-executable
v vc-git-program (tramp-get-remote-path v)))))
- (setq vc-handled-backends (delq 'Git vc-handled-backends)))
+ (setq vc-handled-backends (remq 'Git vc-handled-backends)))
(when (and (memq 'Hg vc-handled-backends)
(boundp 'vc-hg-program)
(not (with-tramp-connection-property v vc-hg-program
(tramp-find-executable
v vc-hg-program (tramp-get-remote-path v)))))
- (setq vc-handled-backends (delq 'Hg vc-handled-backends)))
+ (setq vc-handled-backends (remq 'Hg vc-handled-backends)))
;; Run.
(ignore-errors
(tramp-run-real-handler 'vc-registered (list file))))))))
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#18535: tramp alters `vc-handled-backends'
2014-09-25 7:10 ` Emilio Lopes
@ 2014-09-25 13:07 ` Stefan Monnier
0 siblings, 0 replies; 4+ messages in thread
From: Stefan Monnier @ 2014-09-25 13:07 UTC (permalink / raw)
To: Emilio Lopes; +Cc: 18535-done
>> The current code uses a `let' binding, which uses the same mechanism as
>> unwind-protect, so I don't think that's the source of a the problem.
> Is this common behavior in Lisps? I could not find any reference to
> this in the Elisp manual.
The Elisp manual's description is not in terms of implementation, so it
doesn't say that, but it does document that behavior. E.g.:
When that local binding is no longer in effect, the
previously shadowed value (or lack of one) comes back.
>> The `delq' look dangerous on the other hand. Shouldn't these be
>> `remq' instead?
> yes, this seems to solve the problem.
Thanks, installed,
Stefan
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-09-25 13:07 UTC | newest]
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2014-09-23 10:53 bug#18535: tramp alters `vc-handled-backends' Emilio Lopes
2014-09-23 15:37 ` Stefan Monnier
2014-09-25 7:10 ` Emilio Lopes
2014-09-25 13:07 ` Stefan Monnier
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