unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
* bug#46701: [PATCH] small cleanups related to `unlock-buffer'
@ 2021-02-22  4:18 Matt Armstrong
  2021-02-22 16:27 ` Eli Zaretskii
  0 siblings, 1 reply; 6+ messages in thread
From: Matt Armstrong @ 2021-02-22  4:18 UTC (permalink / raw)
  To: 46701

[-- Attachment #1: Type: text/plain, Size: 128 bytes --]

Two patches here, each removing code that has no effect or discernable
purpose.  I found these while working on a related bug.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: Remove unecessary `unlock-buffer' calls. --]
[-- Type: text/x-patch, Size: 1500 bytes --]

From da42de650842b2d05da42bbbef9e61e8a747b1ff Mon Sep 17 00:00:00 2001
From: Matt Armstrong <matt@rfc20.org>
Date: Wed, 17 Feb 2021 16:47:18 -0800
Subject: [PATCH 1/4] Remove unecessary (unlock-buffer) calls.

* lisp/type-break.el (type-break-mode): Remove an (unlock-buffer) call
implied by (set-buffer-modified nil).
* lisp/simple.el (primitive-undo): ditto.
---
 lisp/simple.el     | 2 --
 lisp/type-break.el | 1 -
 2 files changed, 3 deletions(-)

diff --git a/lisp/simple.el b/lisp/simple.el
index 26710e6d53..4f5a9c5e83 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -3041,8 +3041,6 @@ primitive-undo
                      (and (consp time)
                           (equal (list (car time) (cdr time))
                                  (visited-file-modtime))))
-             (when (fboundp 'unlock-buffer)
-               (unlock-buffer))
              (set-buffer-modified-p nil)))
           ;; Element (nil PROP VAL BEG . END) is property change.
           (`(nil . ,(or `(,prop ,val ,beg . ,end) pcase--dontcare))
diff --git a/lisp/type-break.el b/lisp/type-break.el
index a6d5cd0170..984256d3ce 100644
--- a/lisp/type-break.el
+++ b/lisp/type-break.el
@@ -395,7 +395,6 @@ type-break-mode
       (with-current-buffer (find-file-noselect type-break-file-name
                                                'nowarn)
         (set-buffer-modified-p nil)
-        (unlock-buffer)
         (kill-current-buffer))))))
 
 (define-minor-mode type-break-mode-line-message-mode
-- 
2.30.0


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #3: Remove unecessary let bind. --]
[-- Type: text/x-patch, Size: 1063 bytes --]

From 52c83a2d059ee2e3a22fd5c1e3eece13af169586 Mon Sep 17 00:00:00 2001
From: Matt Armstrong <matt@rfc20.org>
Date: Wed, 17 Feb 2021 16:36:39 -0800
Subject: [PATCH 2/4] Remove unecessary `buffer-file-name' let bind.

* lisp/files.el (revert-buffer-insert-file-contents--default-function):
Do not bind `buffer-file-name' around call to (unlock-buffer);
it has no effect.
---
 lisp/files.el | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/lisp/files.el b/lisp/files.el
index 68e883513c..962137f18c 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -6234,11 +6234,8 @@ revert-buffer-insert-file-contents--default-function
              "Cannot revert unreadable file %s")
            file-name))
    (t
-    ;; Bind buffer-file-name to nil
-    ;; so that we don't try to lock the file.
-    (let ((buffer-file-name nil))
-      (or auto-save-p
-          (unlock-buffer)))
+    (unless auto-save-p
+      (unlock-buffer))
     (widen)
     (let ((coding-system-for-read
            ;; Auto-saved file should be read by Emacs's
-- 
2.30.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* bug#46701: [PATCH] small cleanups related to `unlock-buffer'
  2021-02-22  4:18 bug#46701: [PATCH] small cleanups related to `unlock-buffer' Matt Armstrong
@ 2021-02-22 16:27 ` Eli Zaretskii
  2021-02-23  0:56   ` Matt Armstrong
  0 siblings, 1 reply; 6+ messages in thread
From: Eli Zaretskii @ 2021-02-22 16:27 UTC (permalink / raw)
  To: Matt Armstrong; +Cc: 46701

> From: Matt Armstrong <matt@rfc20.org>
> Date: Sun, 21 Feb 2021 20:18:44 -0800
> 
> Subject: [PATCH 1/4] Remove unecessary (unlock-buffer) calls.
> 
> * lisp/type-break.el (type-break-mode): Remove an (unlock-buffer) call
> implied by (set-buffer-modified nil).
> * lisp/simple.el (primitive-undo): ditto.

My reading of the code is that the above is true only if
inhibit-modification-hooks is nil.  Otherwise, these calls are not
no-ops.

> --- a/lisp/files.el
> +++ b/lisp/files.el
> @@ -6234,11 +6234,8 @@ revert-buffer-insert-file-contents--default-function
>               "Cannot revert unreadable file %s")
>             file-name))
>     (t
> -    ;; Bind buffer-file-name to nil
> -    ;; so that we don't try to lock the file.
> -    (let ((buffer-file-name nil))
> -      (or auto-save-p
> -          (unlock-buffer)))
> +    (unless auto-save-p
> +      (unlock-buffer))

And here, I think we just forgot to update the Lisp code when
unlock-buffer started to look at buffer-file-truename instead of
buffer-file-name.  But otherwise, I see no reason why we should remove
the call to unlock-buffer; what did I miss?

Thanks.





^ permalink raw reply	[flat|nested] 6+ messages in thread

* bug#46701: [PATCH] small cleanups related to `unlock-buffer'
  2021-02-22 16:27 ` Eli Zaretskii
@ 2021-02-23  0:56   ` Matt Armstrong
  2021-02-26  0:45     ` Stefan Kangas
  2021-02-27 14:22     ` Eli Zaretskii
  0 siblings, 2 replies; 6+ messages in thread
From: Matt Armstrong @ 2021-02-23  0:56 UTC (permalink / raw)
  To: Eli Zaretskii; +Cc: 46701

[-- Attachment #1: Type: text/plain, Size: 2951 bytes --]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Matt Armstrong <matt@rfc20.org>
>> Date: Sun, 21 Feb 2021 20:18:44 -0800
>> 
>> Subject: [PATCH 1/4] Remove unecessary (unlock-buffer) calls.
>> 
>> * lisp/type-break.el (type-break-mode): Remove an (unlock-buffer) call
>> implied by (set-buffer-modified nil).
>> * lisp/simple.el (primitive-undo): ditto.
>
> My reading of the code is that the above is true only if
> inhibit-modification-hooks is nil.  Otherwise, these calls are not
> no-ops.

Thanks, good catch.  I think the change to type-break.el is probably
fine, but I will drop it for now.  In simple.el I just removed the
unecessary fboundp check (new patch attached).


>> --- a/lisp/files.el
>> +++ b/lisp/files.el
>> @@ -6234,11 +6234,8 @@ revert-buffer-insert-file-contents--default-function
>>               "Cannot revert unreadable file %s")
>>             file-name))
>>     (t
>> -    ;; Bind buffer-file-name to nil
>> -    ;; so that we don't try to lock the file.
>> -    (let ((buffer-file-name nil))
>> -      (or auto-save-p
>> -          (unlock-buffer)))
>> +    (unless auto-save-p
>> +      (unlock-buffer))
>
> And here, I think we just forgot to update the Lisp code when
> unlock-buffer started to look at buffer-file-truename instead of
> buffer-file-name.  But otherwise, I see no reason why we should remove
> the call to unlock-buffer; what did I miss?

This is some very old code.

When originally written the `unlock-buffer' was a nop because it was
well before file-buffer-truename existed -- the let bind disabled it.
The let bind was intended to prevent locking the buffer by
`erase-buffer'.  See Roland's commit below, which is the first commit
for this file that we've got.


b4da00e92a0 (Roland McGrath      1991-07-19 1804)

;; Bind buffer-file-name to nil
;; so that we don't try to lock the file.
(let ((buffer-file-name nil))
  (or auto-save-p
      (unlock-buffer))
  (erase-buffer))
(insert-file-contents file-name (not auto-save-p))))


A few years later Richard moved the erase logic to insert-file-contents,
but left the no-op call to unlock-buffer.  Note that the comment no
longer makes sense.

f9456b0a5b5 (Richard M. Stallman 1994-02-17 2020)

;; Bind buffer-file-name to nil
;; so that we don't try to lock the file.
(let ((buffer-file-name nil))
  (or auto-save-p
      (unlock-buffer))
(insert-file-contents file-name (not auto-save-p)
                      nil nil t)))


insert-file-contents has logic to unlock the buffer. I must admit that I
don't understand how that logic works.

When unlock-buffer switched to using buffer-file-tempfile the
unlock-buffer call here became active for the first time, probably by
accident?  Removing it now is a possible behavior change, but it
restores the original behavior.

I did a manual test.  I edited a file, then changed the file outside
emacs, then ran revert-buffer.  The file's lock file was still removed,
even with the patch below applied.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-Remove-unecessary-unlock-buffer-call.patch --]
[-- Type: text/x-patch, Size: 947 bytes --]

From 3b569a6b9139d2b350745bebc64db506728cf994 Mon Sep 17 00:00:00 2001
From: Matt Armstrong <matt@rfc20.org>
Date: Mon, 22 Feb 2021 16:40:05 -0800
Subject: [PATCH 1/2] Remove unecessary unlock-buffer call.

* lisp/files.el (revert-buffer-insert-file-contents--default-function):
Remove vestigial call to `unlock-buffer'.
---
 lisp/files.el | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/lisp/files.el b/lisp/files.el
index 68e883513c..b5d92cd841 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -6234,11 +6234,6 @@ revert-buffer-insert-file-contents--default-function
              "Cannot revert unreadable file %s")
            file-name))
    (t
-    ;; Bind buffer-file-name to nil
-    ;; so that we don't try to lock the file.
-    (let ((buffer-file-name nil))
-      (or auto-save-p
-          (unlock-buffer)))
     (widen)
     (let ((coding-system-for-read
            ;; Auto-saved file should be read by Emacs's
-- 
2.30.0


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #3: 0002-Assume-unlock-buffer-is-always-bound.patch --]
[-- Type: text/x-patch, Size: 980 bytes --]

From dc9cc451e0ab6a84d839f3ed9d1b552da3c43373 Mon Sep 17 00:00:00 2001
From: Matt Armstrong <matt@rfc20.org>
Date: Mon, 22 Feb 2021 16:41:44 -0800
Subject: [PATCH 2/2] Assume unlock-buffer is always bound.

* lisp/simple.el (primitive-undo): Assume unlock-buffer is always
bound.
---
 lisp/simple.el | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lisp/simple.el b/lisp/simple.el
index 1dfc3374ad..c4062d97cc 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -3043,8 +3043,7 @@ primitive-undo
                      (and (consp time)
                           (equal (list (car time) (cdr time))
                                  (visited-file-modtime))))
-             (when (fboundp 'unlock-buffer)
-               (unlock-buffer))
+             (unlock-buffer)
              (set-buffer-modified-p nil)))
           ;; Element (nil PROP VAL BEG . END) is property change.
           (`(nil . ,(or `(,prop ,val ,beg . ,end) pcase--dontcare))
-- 
2.30.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* bug#46701: [PATCH] small cleanups related to `unlock-buffer'
  2021-02-23  0:56   ` Matt Armstrong
@ 2021-02-26  0:45     ` Stefan Kangas
  2021-02-27 14:22     ` Eli Zaretskii
  1 sibling, 0 replies; 6+ messages in thread
From: Stefan Kangas @ 2021-02-26  0:45 UTC (permalink / raw)
  To: Matt Armstrong; +Cc: 46701

Matt Armstrong <matt@rfc20.org> writes:

> I did a manual test.  I edited a file, then changed the file outside
> emacs, then ran revert-buffer.  The file's lock file was still removed,
> even with the patch below applied.

Perhaps we should write some automatic tests before changing anything in
this area?





^ permalink raw reply	[flat|nested] 6+ messages in thread

* bug#46701: [PATCH] small cleanups related to `unlock-buffer'
  2021-02-23  0:56   ` Matt Armstrong
  2021-02-26  0:45     ` Stefan Kangas
@ 2021-02-27 14:22     ` Eli Zaretskii
  2021-02-27 14:24       ` Eli Zaretskii
  1 sibling, 1 reply; 6+ messages in thread
From: Eli Zaretskii @ 2021-02-27 14:22 UTC (permalink / raw)
  To: Matt Armstrong; +Cc: 46701

> From: Matt Armstrong <matt@rfc20.org>
> Cc: 46701@debbugs.gnu.org
> Date: Mon, 22 Feb 2021 16:56:44 -0800
> 
> Thanks, good catch.  I think the change to type-break.el is probably
> fine, but I will drop it for now.  In simple.el I just removed the
> unecessary fboundp check (new patch attached).

Thanks, pushed to the master branch.





^ permalink raw reply	[flat|nested] 6+ messages in thread

* bug#46701: [PATCH] small cleanups related to `unlock-buffer'
  2021-02-27 14:22     ` Eli Zaretskii
@ 2021-02-27 14:24       ` Eli Zaretskii
  0 siblings, 0 replies; 6+ messages in thread
From: Eli Zaretskii @ 2021-02-27 14:24 UTC (permalink / raw)
  To: matt; +Cc: 46701-done

> Date: Sat, 27 Feb 2021 16:22:26 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 46701@debbugs.gnu.org
> 
> > From: Matt Armstrong <matt@rfc20.org>
> > Cc: 46701@debbugs.gnu.org
> > Date: Mon, 22 Feb 2021 16:56:44 -0800
> > 
> > Thanks, good catch.  I think the change to type-break.el is probably
> > fine, but I will drop it for now.  In simple.el I just removed the
> > unecessary fboundp check (new patch attached).
> 
> Thanks, pushed to the master branch.

And with that, I'm closing this bug report.





^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-02-27 14:24 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-02-22  4:18 bug#46701: [PATCH] small cleanups related to `unlock-buffer' Matt Armstrong
2021-02-22 16:27 ` Eli Zaretskii
2021-02-23  0:56   ` Matt Armstrong
2021-02-26  0:45     ` Stefan Kangas
2021-02-27 14:22     ` Eli Zaretskii
2021-02-27 14:24       ` Eli Zaretskii

Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).