bug with using :move on folds?

[Ein Brown]

Hi, I have encountered a bug where my folds become 'corrupted' and unrecognized by vim. I looks like this is caused by using :move on a closed fold under the right circumstances.

The SO question has more details:
http://stackoverflow.com/questions/16592654/in-vim-why-is-move-randomly-corrupting-my-folds

at the bottom of the SO question (under 'edit') I explain ways to run into the bug without the Alt-Up / Alt-Down mapping.

Best,
Ein

[Christian Brabandt]

Hi Ein!

I just saw the problem yesterday. Here is an simpler example of the bug:
#v+
chrisbra@R500 % cat foldmarker_bug.txt
vim: fdm=marker



fold A {{{
some
text
here
}}}
fold B {{{
some
text
here
}}}
fold C {{{
some
text
here
}}}
fold D {{{
some
text
here
}}}
chrisbra@R500 vim -u NONE -N foldmarker_bug.txt
:10
:4m
#v-

Note, that the fold B stays open and it is not possible to close
it. Debugging it with gdb, you'll find, that wp->w_folds get invalid
(e.g. is out of order).

I think this patch fixes it.
iff --git a/src/ex_cmds.c b/src/ex_cmds.c
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -784,6 +784,7 @@
*/
last_line = curbuf->b_ml.ml_line_count;
mark_adjust(line1, line2, last_line - line2, 0L);
+ changed_lines(last_line - num_lines + 1, 0, last_line + 1, num_lines);
if (dest >= line2)
{
mark_adjust(line2 + 1, dest, -num_lines, 0L);
@@ -800,6 +801,7 @@
mark_adjust(last_line - num_lines + 1, last_line,
-(last_line - dest - extra), 0L);

+ changed_lines(last_line - num_lines + 1, 0, last_line + 1, -extra);
/*
* Now we delete the original text -- webb
*/


BTW: I think, there is also an error in fold.c:
diff --git a/src/fold.c b/src/fold.c
--- a/src/fold.c
+++ b/src/fold.c
@@ -849,8 +849,8 @@
fold_T *fp;

/* Mark all folds from top to bot as maybe-small. */
- (void)foldFind(&curwin->w_folds, top, &fp);
- while (fp < (fold_T *)curwin->w_folds.ga_data + curwin->w_folds.ga_len
+ (void)foldFind(&wp->w_folds, top, &fp);
+ while (fp < (fold_T *)wp->w_folds.ga_data + wp->w_folds.ga_len
&& fp->fd_top < bot)
{
fp->fd_small = MAYBE;



regards,
Christian
--

[Christian Brabandt]

On Fr, 24 Mai 2013, Christian Brabandt wrote:

> On Fr, 24 Mai 2013, Ein Brown wrote:
>
> > The SO question has more details:
> > http://stackoverflow.com/questions/16592654/in-vim-why-is-move-randomly-corrupting-my-folds
> >
> > at the bottom of the SO question (under 'edit') I explain ways to run into the bug without the Alt-Up / Alt-Down mapping.
>
> I just saw the problem yesterday. Here is an simpler example of the bug:
>

> I think this patch fixes it.

[...]

No, it doesn't fix it completely. I'll look into it some more.

regards,
Christian
--
Der Glaube versetzt Berge, der Zweifel erklettert sie.
-- Karl Heinrich Waggerl

[Bram Moolenaar]

[...]

Thanks.

> BTW: I think, there is also an error in fold.c:

[...]

Yep.


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[Bram Moolenaar]

Christian Brabandt wrote:

> On Fr, 24 Mai 2013, Christian Brabandt wrote:
>
> > On Fr, 24 Mai 2013, Ein Brown wrote:
> >
> > > The SO question has more details:
> > > http://stackoverflow.com/questions/16592654/in-vim-why-is-move-randomly-corrupting-my-folds
> > >
> > > at the bottom of the SO question (under 'edit') I explain ways to run into the bug without the Alt-Up / Alt-Down mapping.
> >
> > I just saw the problem yesterday. Here is an simpler example of the bug:
> >
> > I think this patch fixes it.
> [...]
>
> No, it doesn't fix it completely. I'll look into it some more.

Any progress? What still fails?

--
hundred-and-one symptoms of being an internet addict:
10. And even your night dreams are in HTML.

[Christian Brabandt]

On Wed, May 29, 2013 13:33, Bram Moolenaar wrote:
>
> Christian Brabandt wrote:
>
>> On Fr, 24 Mai 2013, Christian Brabandt wrote:
>>
>> > On Fr, 24 Mai 2013, Ein Brown wrote:
>> >
>> > > The SO question has more details:
>> > > http://stackoverflow.com/questions/16592654/in-vim-why-is-move-randomly-corrupting-my-folds
>> > >
>> > > at the bottom of the SO question (under 'edit') I explain ways to
>> run into the bug without the Alt-Up / Alt-Down mapping.
>> >
>> > I just saw the problem yesterday. Here is an simpler example of the
>> bug:
>> >
>> > I think this patch fixes it.
>> [...]
>>
>> No, it doesn't fix it completely. I'll look into it some more.
>
> Any progress? What still fails?
>

No, I can't figure out why curwin->w_folds gets out of order and
also sometimes many more folds.
I haven't really figured out the complete foldUpdate process yet.

regards,
Christian

[Bram Moolenaar]

Christian Brabandt wrote:

> On Fr, 24 Mai 2013, Christian Brabandt wrote:
>
> > On Fr, 24 Mai 2013, Ein Brown wrote:
> >
> > > The SO question has more details:
> > > http://stackoverflow.com/questions/16592654/in-vim-why-is-move-randomly-corrupting-my-folds
> > >
> > > at the bottom of the SO question (under 'edit') I explain ways to run into the bug without the Alt-Up / Alt-Down mapping.
> >
> > I just saw the problem yesterday. Here is an simpler example of the bug:
> >
> > I think this patch fixes it.
> [...]
>
> No, it doesn't fix it completely. I'll look into it some more.

I accidentally included some of this in patch 7.3.1042.
I hope it doesn't cause any problems...

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[Christian Brabandt]

Hi Bram!

On Do, 30 Mai 2013, Bram Moolenaar wrote:

> Christian Brabandt wrote:
>
> > On Fr, 24 Mai 2013, Christian Brabandt wrote:
> >
> > > On Fr, 24 Mai 2013, Ein Brown wrote:
> > >
> > > > The SO question has more details:
> > > > http://stackoverflow.com/questions/16592654/in-vim-why-is-move-randomly-corrupting-my-folds
> > > >
> > > > at the bottom of the SO question (under 'edit') I explain ways to run into the bug without the Alt-Up / Alt-Down mapping.
> > >
> > > I just saw the problem yesterday. Here is an simpler example of the bug:
> > >
> > > I think this patch fixes it.
> > [...]
> >
> > No, it doesn't fix it completely. I'll look into it some more.
>
> I accidentally included some of this in patch 7.3.1042.
> I hope it doesn't cause any problems...

Opps, well it fixes a particular problem, but is not a complete
solution.

regards,
Christian
--
Steine sind stumme Lehrer, sie machen den Beobachter stumm, und
das Beste, was man von ihnen lernt, ist nicht mitzuteilen.
-- Goethe, Maximen und Reflektionen, Nr. 853

[Christian Brabandt]

Well here is a patch, that deletes the foldinfo and recreates it after
moving is finished. Admittedly, this doesn't solve the problem, but I
think it is actually simpler to delete and recreate the fold info, then
to update the curwin->w_folds several times for a single :move command.

This patch is against 7.3.1006, so does not include the changes
introduced by 7.3.1042.

regards,
Christian