* diff-find-file-name and /dev/null
@ 2007-08-17 22:53 Nikolaj Schumacher
2007-08-17 23:33 ` Michaël Cadilhac
0 siblings, 1 reply; 6+ messages in thread
From: Nikolaj Schumacher @ 2007-08-17 22:53 UTC (permalink / raw)
To: bug-gnu-emacs
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Hello,
using diff files (from git) that create new files like this:
--- /dev/null
+++ b/foo/bar.c
I noticed that `diff-goto-source' opens /dev/null, which is usually not
desirable. I use the attached small change to get the actual file.
regards,
Nikolaj Schumacher
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--- lisp/diff-mode.el 2007-08-17 06:03:27.000000000 +0200
+++ lisp/diff-mode.el 2007-08-18 00:48:25.000000000 +0200
@@ -667,6 +667,7 @@
(or (ignore-errors (diff-beginning-of-file))
(re-search-forward diff-file-header-re nil t)))
(let ((fs (diff-hunk-file-names old)))
+ (setq fs (delete "/dev/null" fs))
(if prefix (setq fs (mapcar (lambda (f) (concat prefix f)) fs)))
(or
;; use any previously used preference
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: diff-find-file-name and /dev/null
2007-08-17 22:53 diff-find-file-name and /dev/null Nikolaj Schumacher
@ 2007-08-17 23:33 ` Michaël Cadilhac
2007-08-19 21:06 ` Nikolaj Schumacher
0 siblings, 1 reply; 6+ messages in thread
From: Michaël Cadilhac @ 2007-08-17 23:33 UTC (permalink / raw)
To: Nikolaj Schumacher; +Cc: bug-gnu-emacs
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Nikolaj Schumacher <n_schumacher@web.de> writes:
> Hello,
>
> using diff files (from git) that create new files like this:
>
> --- /dev/null
> +++ b/foo/bar.c
>
> I noticed that `diff-goto-source' opens /dev/null, which is usually not
> desirable. I use the attached small change to get the actual file.
Just for my information, why do you think it's not a good thing?
--
| Michaël `Micha' Cadilhac | La culture c'est comme la confiture, |
| http://michael.cadilhac.name | c'est meilleur avec du pain. |
| JID/MSN: | -- MOI59 |
`---- michael.cadilhac@gmail.com | - --'
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: diff-find-file-name and /dev/null
2007-08-17 23:33 ` Michaël Cadilhac
@ 2007-08-19 21:06 ` Nikolaj Schumacher
2007-08-25 1:54 ` Glenn Morris
0 siblings, 1 reply; 6+ messages in thread
From: Nikolaj Schumacher @ 2007-08-19 21:06 UTC (permalink / raw)
To: bug-gnu-emacs
michael@cadilhac.name (Michaël Cadilhac) wrote:
> Nikolaj Schumacher <n_schumacher@web.de> writes:
>
>> --- /dev/null
>> +++ b/foo/bar.c
>>
>> I noticed that `diff-goto-source' opens /dev/null, which is usually not
>> desirable. I use the attached small change to get the actual file.
>
> Just for my information, why do you think it's not a good thing?
Since there's nothing to view or edit in /dev/null.
Also in a usual diff file
--- /dev/null 2007-08-17 06:03:27.000000000 +0200
+++ /foo/bar.c 2007-08-18 00:48:25.000000000 +0200
`diff-goto-source' would visit /foo/bar.c
git's peculiar a/ b/ prefixes are the problem here. Usually it works,
because `diff-find-file-name' chops those off, if the file doesn't
exist. It will try b/foo/bar.c first. But then /dev/null, before
foo/bar.c.
I admit the actual fault could be the fact that it looks for first one
at all (or at least _before_ chopping off prefixes of the second one),
even when diff-jump-to-old-file is nil. /dev/null is just the only
cause of such behavior.
regards,
Nikolaj Schumacher
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: diff-find-file-name and /dev/null
2007-08-19 21:06 ` Nikolaj Schumacher
@ 2007-08-25 1:54 ` Glenn Morris
2007-08-27 4:51 ` Stefan Monnier
0 siblings, 1 reply; 6+ messages in thread
From: Glenn Morris @ 2007-08-25 1:54 UTC (permalink / raw)
To: Nikolaj Schumacher; +Cc: bug-gnu-emacs, Stefan Monnier
Nikolaj Schumacher wrote:
> Since there's nothing to view or edit in /dev/null.
How about this patch then:
diff -c -c -w -r1.99.2.3 diff-mode.el
*** diff-mode.el 6 Aug 2007 20:08:07 -0000 1.99.2.3
--- diff-mode.el 25 Aug 2007 01:41:53 -0000
***************
*** 646,652 ****
((or (null files)
(setq file (do* ((files files (cdr files))
(file (car files) (car files)))
! ((or (null file) (file-exists-p file))
file))))
file))
;; <foo>.rej patches implicitly apply to <foo>
--- 646,652 ----
((or (null files)
(setq file (do* ((files files (cdr files))
(file (car files) (car files)))
! ((or (null file) (file-regular-p file))
file))))
file))
;; <foo>.rej patches implicitly apply to <foo>
> Also in a usual diff file
>
> --- /dev/null 2007-08-17 06:03:27.000000000 +0200
> +++ /foo/bar.c 2007-08-18 00:48:25.000000000 +0200
>
> `diff-goto-source' would visit /foo/bar.c
It's easy to produce a non-git diff that has the same behaviour. Just
do a diff between /dev/null and a relative filename:
diff -u /dev/null foo/somefile > foo/some.diff
Then open foo/some.diff in Emacs and try to jump to source. I'd never
make a hideous diff like that though...
> I admit the actual fault could be the fact that it looks for first
> one at all (or at least _before_ chopping off prefixes of the second
> one), even when diff-jump-to-old-file is nil. /dev/null is just the
> only cause of such behavior.
Yes, I don't see why diff-find-file-name does that, and I don't think
/dev/null is the only cause. Eg repeating the above example, but with
regular files:
diff -u /tmp/file1 foo/file2 > foo/file.diff
diff-goto-source will open file1 rather than file2.
Stefan, is there a reason why diff-find-file-name can return the old
file, even when OLD is nil? Why doesn't it just consider
(car (diff-hunk-file-names old))?
If it should consider both old and new in each case, should it not try
dropping the directory entries from the new/old file first, before
going on to check the old/new one in the same way only it it does not
find a match?
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: diff-find-file-name and /dev/null
2007-08-25 1:54 ` Glenn Morris
@ 2007-08-27 4:51 ` Stefan Monnier
2007-08-27 7:10 ` Glenn Morris
0 siblings, 1 reply; 6+ messages in thread
From: Stefan Monnier @ 2007-08-27 4:51 UTC (permalink / raw)
To: Glenn Morris; +Cc: Nikolaj Schumacher, bug-gnu-emacs
>> Since there's nothing to view or edit in /dev/null.
> How about this patch then:
> diff -c -c -w -r1.99.2.3 diff-mode.el
> *** diff-mode.el 6 Aug 2007 20:08:07 -0000 1.99.2.3
> --- diff-mode.el 25 Aug 2007 01:41:53 -0000
> ***************
> *** 646,652 ****
> ((or (null files)
> (setq file (do* ((files files (cdr files))
> (file (car files) (car files)))
> ! ((or (null file) (file-exists-p file))
> file))))
> file))
> ;; <foo>.rej patches implicitly apply to <foo>
> --- 646,652 ----
> ((or (null files)
> (setq file (do* ((files files (cdr files))
> (file (car files) (car files)))
> ! ((or (null file) (file-regular-p file))
> file))))
> file))
> ;; <foo>.rej patches implicitly apply to <foo>
Looks very good. This will also rule out directories. Please install.
>> I admit the actual fault could be the fact that it looks for first
>> one at all (or at least _before_ chopping off prefixes of the second
>> one), even when diff-jump-to-old-file is nil. /dev/null is just the
>> only cause of such behavior.
> Yes, I don't see why diff-find-file-name does that, and I don't think
> /dev/null is the only cause. Eg repeating the above example, but with
> regular files:
> diff -u /tmp/file1 foo/file2 > foo/file.diff
> diff-goto-source will open file1 rather than file2.
> Stefan, is there a reason why diff-find-file-name can return the old
> file, even when OLD is nil? Why doesn't it just consider
> (car (diff-hunk-file-names old))?
diff-find-file-name tries pretty hard to find *A* file, so I think it's
OK for it to sometimes return an old file even when OLD is nil.
But maybe the order in which file names are tried could be improved.
> If it should consider both old and new in each case, should it not try
> dropping the directory entries from the new/old file first, before
> going on to check the old/new one in the same way only it it does not
> find a match?
Sounds right. The current ordering is somewhat arbitrary. Fell free to
change it as you suggest, but for any such change, please add a comment
explaining the situation for which the change makes sense.
Stefan
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: diff-find-file-name and /dev/null
2007-08-27 4:51 ` Stefan Monnier
@ 2007-08-27 7:10 ` Glenn Morris
0 siblings, 0 replies; 6+ messages in thread
From: Glenn Morris @ 2007-08-27 7:10 UTC (permalink / raw)
To: Stefan Monnier; +Cc: Nikolaj Schumacher, bug-gnu-emacs
Stefan Monnier wrote:
> Looks very good. This will also rule out directories. Please install.
OK, installed on release branch.
> Sounds right. The current ordering is somewhat arbitrary. Fell free to
> change it as you suggest, but for any such change, please add a comment
> explaining the situation for which the change makes sense.
OK, I may look at doing this on the trunk.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2007-08-27 7:10 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2007-08-17 22:53 diff-find-file-name and /dev/null Nikolaj Schumacher
2007-08-17 23:33 ` Michaël Cadilhac
2007-08-19 21:06 ` Nikolaj Schumacher
2007-08-25 1:54 ` Glenn Morris
2007-08-27 4:51 ` Stefan Monnier
2007-08-27 7:10 ` Glenn Morris
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