* Minor bug in c-beginning-of-defun. May I fix it?
@ 2007-04-17 18:21 Alan Mackenzie
2007-04-17 19:07 ` Chong Yidong
0 siblings, 1 reply; 5+ messages in thread
From: Alan Mackenzie @ 2007-04-17 18:21 UTC (permalink / raw)
To: Chong Yidong, emacs-devel
Hi, Chong and Emacs!
Open (for example) ..../src/cmds.c and move point to within the braces
of the last function, `keys_of_cmds'. Do M-- C-M-a.
Since there is no next defun, point should be left at EOB. It is,
sadly, erroneously left after the last closing brace.
The fix is straightforward: The third argument NOERROR to a
`c-syntactic-re-search-forward' should not be t; it should be something
else non-nil. So, when a search fails, point will be left at EOB rather
than unmoved. The argument `NOERROR' here has the same meaning it does
in the Emacs core function `search-forward-regexp'.
I believe this patch is safe and trouble free. Please tell me to commit
it!
2007-04-17 Alan Mackenzie <acm@muc.de>
* progmodes/cc-cmds.el (c-beginning-of-defun): With -ve arg and
point too close to EOB, leave point at EOB rather than last `}'.
Index: cc-cmds.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/progmodes/cc-cmds.el,v
retrieving revision 1.58
diff -c -r1.58 cc-cmds.el
*** cc-cmds.el 9 Apr 2007 10:51:29 -0000 1.58
--- cc-cmds.el 17 Apr 2007 18:04:26 -0000
***************
*** 1531,1537 ****
(setq arg (c-forward-to-nth-EOF-} (- arg) where)))
;; Move forward to the next opening brace....
(when (and (= arg 0)
! (c-syntactic-re-search-forward "{" nil t))
(backward-char)
;; ... and backward to the function header.
(c-beginning-of-decl-1)
--- 1531,1537 ----
(setq arg (c-forward-to-nth-EOF-} (- arg) where)))
;; Move forward to the next opening brace....
(when (and (= arg 0)
! (c-syntactic-re-search-forward "{" nil 'eob))
(backward-char)
;; ... and backward to the function header.
(c-beginning-of-decl-1)
--
Alan Mackenzie (Ittersbach, Germany).
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Minor bug in c-beginning-of-defun. May I fix it?
2007-04-17 18:21 Minor bug in c-beginning-of-defun. May I fix it? Alan Mackenzie
@ 2007-04-17 19:07 ` Chong Yidong
2007-04-17 19:47 ` Alan Mackenzie
0 siblings, 1 reply; 5+ messages in thread
From: Chong Yidong @ 2007-04-17 19:07 UTC (permalink / raw)
To: Alan Mackenzie; +Cc: emacs-devel
Alan Mackenzie <acm@muc.de> writes:
> The fix is straightforward: The third argument NOERROR to a
> `c-syntactic-re-search-forward' should not be t; it should be something
> else non-nil. So, when a search fails, point will be left at EOB rather
> than unmoved. The argument `NOERROR' here has the same meaning it does
> in the Emacs core function `search-forward-regexp'.
>
> ! (c-syntactic-re-search-forward "{" nil t))
> --- 1531,1537 ----
> ! (c-syntactic-re-search-forward "{" nil 'eob))
Hi Alan,
I played around with your patch a little, and noticed that it
introduces a slight difference in the behavior of
c-beginning-of-defun. Consider the following file (not including the
"----" characters, and including the final "\n\n"):
-------------------
int foo ()
{
asdf;
if (asdf)
{
bar;
}
}
-------------------
With point at bob, do C-u -1 M-x c-beginning-of-defun RET.
Before the change, point moves to the newline just after the last }
character, and on the same line. After the change, it moves one
additional line down.
I guess this is harmless, but could you double-check? (Otherwise, the
change looks OK to me, assuming you've tested it out thoroughly.)
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Minor bug in c-beginning-of-defun. May I fix it?
2007-04-17 19:07 ` Chong Yidong
@ 2007-04-17 19:47 ` Alan Mackenzie
2007-04-17 20:04 ` Chong Yidong
0 siblings, 1 reply; 5+ messages in thread
From: Alan Mackenzie @ 2007-04-17 19:47 UTC (permalink / raw)
To: Chong Yidong; +Cc: emacs-devel
Hi, Chong!
On Tue, Apr 17, 2007 at 03:07:36PM -0400, Chong Yidong wrote:
> Alan Mackenzie <acm@muc.de> writes:
> > ! (c-syntactic-re-search-forward "{" nil t))
> > --- 1531,1537 ----
> > ! (c-syntactic-re-search-forward "{" nil 'eob))
> Hi Alan,
> I played around with your patch a little, and noticed that it
> introduces a slight difference in the behavior of
> c-beginning-of-defun. Consider the following file (not including the
> "----" characters, and including the final "\n\n"):
> -------------------
> int foo ()
> {
> asdf;
> if (asdf)
> {
> bar;
> }
> }
> -------------------
> With point at bob, do C-u -1 M-x c-beginning-of-defun RET.
> Before the change, point moves to the newline just after the last }
> character, and on the same line.
This was the bug. Just after the } is NOT a beginning-of-defun.
> After the change, it moves one additional line down.
> I guess this is harmless, but could you double-check?
The new behaviour is correct: c-beginning-of-defun should emulate the
standard b-o-d; the only places point should end up at are a BOD or
[BE]OB.
> (Otherwise, the change looks OK to me, assuming you've tested it out
> thoroughly.)
I've tested it thoroughly.
--
Alan.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Minor bug in c-beginning-of-defun. May I fix it?
2007-04-17 19:47 ` Alan Mackenzie
@ 2007-04-17 20:04 ` Chong Yidong
2007-04-17 20:50 ` Alan Mackenzie
0 siblings, 1 reply; 5+ messages in thread
From: Chong Yidong @ 2007-04-17 20:04 UTC (permalink / raw)
To: Alan Mackenzie; +Cc: emacs-devel
Alan Mackenzie <acm@muc.de> writes:
>> Before the change, point moves to the newline just after the last }
>> character, and on the same line.
>
> This was the bug. Just after the } is NOT a beginning-of-defun.
Ah, OK then.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Minor bug in c-beginning-of-defun. May I fix it?
2007-04-17 20:04 ` Chong Yidong
@ 2007-04-17 20:50 ` Alan Mackenzie
0 siblings, 0 replies; 5+ messages in thread
From: Alan Mackenzie @ 2007-04-17 20:50 UTC (permalink / raw)
To: Chong Yidong; +Cc: emacs-devel
Hi, Chong!
On Tue, Apr 17, 2007 at 04:04:25PM -0400, Chong Yidong wrote:
> Alan Mackenzie <acm@muc.de> writes:
>
> >> Before the change, point moves to the newline just after the last }
> >> character, and on the same line.
> >
> > This was the bug. Just after the } is NOT a beginning-of-defun.
>
> Ah, OK then.
I've committed it.
--
Alan.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2007-04-17 18:21 Minor bug in c-beginning-of-defun. May I fix it? Alan Mackenzie
2007-04-17 19:07 ` Chong Yidong
2007-04-17 19:47 ` Alan Mackenzie
2007-04-17 20:04 ` Chong Yidong
2007-04-17 20:50 ` Alan Mackenzie
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