Re: [PATCH] Clean up temporary file in hardlink mode

[Tom de Vries <tdevries@suse.de>]

On 3/3/21 11:57 PM, Mark Wielaard wrote:
> Hi Tom,
> 
> On Tue, Mar 02, 2021 at 11:10:27AM +0100, Tom de Vries wrote:
>> Consider an executable file with hardlinks a.out and b.out.
>>
>> When running dwz once:
>> ...
>> $ dwz -h a.out b.out
>> ...
>> a.out and b.out are updated, and remain hardlinks to the same file.
>>
>> But when running dwz once more, a.out and b.out remain unchanged, and a
>> temporary file b.out.#dwz#.XXXXXX is left.
>>
>> This is caused by the fact that the code in function dwz that is intended to
>> handle unchanged hardlinks is never triggered.  It is guarded by a
>> "resa[n].res == 1" condition, but res->res is set to 0 at the end of function
>> dwz, irrespective of whether the file changed or not.
>>
>> Fix this by only setting res->res to 0 if the file changed.
> 
> This looks correct. This works because at the start of the dwz
> function res->res is set to -1 (ignore) or 1 (unchanged) and then only
> set to -2 for the hardlink case or 0 if write_dso succeeds.
> 
>> This makes test-case twice-multifile.sh fail, we'll deal with that in a
>> seperate patch.
> 
> I haven't look at that patch yet, but if at all possible I would like
> to get them in together. Or otherwise make the testcase skip. Having
> failing tests in between commits makes things like bisecting a bit
> messy (and will trigger warnings from the buildbots).

Committed them together.

Thanks,
- Tom