bug#61893: 29.0.60; Indentation in c-ts-mode broken again

[Yuan Fu]

> On Mar 5, 2023, at 12:22 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Yuan Fu <casouri@gmail.com>
>> Date: Sat, 4 Mar 2023 15:03:46 -0800
>> Cc: Eli Zaretskii <eliz@gnu.org>,
>> Daniel Martín <mardani29@yahoo.es>,
>> 61893@debbugs.gnu.org
>> 
>>>>>> The elif directive’s and subsequent directives aren’t indented properly. 
>>>>>> Looking at the parsed tree, the elif directives are nested in the if 
>>>>>> directive, and the nesting can be arbitrarily deep. We probably need a 
>>>>>> custom function rather than great-grand-parent to find the anchor, like 
>>>>>> a function that keeps going up the tree until the node isn’t a preproc 
>>>>>> directive anymore.
>>>>>> 
>>>>>> Yuan
>>>>> 
>>>>> Yeah, you're right. I'll see what I can do, but bandwidth is a little low 
>>>>> at the moment, so if you have some extra time, don't hesitate to improve 
>>>>> it :)
>>>> 
>>>> Absolutely, I’ll work on it. 
>>>> 
>>>> Yuan
>>> 
>>> Thanks :)
>> 
>> Done!
> 
> Thanks.
> 
> Some problems still remain.

Thanks, there are so many edge cases :-)

> 
> Line 1761 of dispnew.c: type "C-e RET" -- point goes to column 7
> instead of the expected column 2.

Fixed.
> 
> Line 3381 of dispnew.c: type "C-e RET" -- point goes to the correct
> column, but line 3381 is reindented incorrectly.

This is due to it aligning to the previous sibling, aka the comment. Do we want 
to skip comments for the “align to the prev sibling” rule?

> 
> Line 6611 of dispnew.e: type "C-e RET" -- point goes to column 0
> instead of the expected column 2.  If you type "C-e RET" on the next
> line 6612, point goes to column 0 and the line is reindented
> incorrectly.

Fixed.
> 
> Line 13925 of xdisp.c: type "C-e RET" -- point goes to column 33(!)
> and line 13925 is reindented incorrectly.

Fixed.
> 
> Lines 34529 and 34530 of xdisp.c: "C-e RET" produces incorrect column
> of point and reindents line 34530.

The preproc directive messed the parse tree, and tree-sitter can’t tell that 
it’s an else statement, so it can’t be easily fixed sadly.

Yuan