Jeff King venit, vidit, dixit 07.09.2017 16:54:
> On Thu, Sep 07, 2017 at 04:02:19PM +0200, Michael J Gruber wrote:
>
>> name-rev segfaults for me in emacs.git with the typical 8102 stack size.
>> The reason is the recursive walk that name-rev uses.
>>
>> This series adds a test to mark this as known failure, after some
>> clean-ups.
>
> These all look reasonable to me. The size of the test case in the final
> one is presumably arbitrary and just copied from t7004. I don't know if
> it's worth trying to shrink it. It could shorten a rather expensive
> test. OTOH, if we shorten it too much then we might get a false pass
> (e.g., if the algorithm remains recursive but has a smaller stack
> footprint).
>
>> Michael J Gruber (4):
>> t7004: move limited stack prereq to test-lib
>> t6120: test name-rev --all and --stdin
>> t6120: clean up state after breaking repo
>> t6120: test describe and name-rev with deep repos
>
> Now comes the hard part: rewriting the C code. :)
Looking at it more closely, the solution in cbc60b6720 ("git tag
--contains: avoid stack overflow", 2014-04-24) seems to be a bit "ad
hoc" to me:
First of all, there is more than "tag --contains" that may exceed the
stack by recursion. So I would expect the solution to be more general,
and not localised and specialised to builtin/tag.c
Second, this is a walk, so I'm wondering whether our revision walk
machinery should be the place to add missing functionality (if any).
That way, everything would benefit from possible or existing
improvements there. For example, I think some of our "extra walkers"
don't heed object replacements. (I need to test more.)
Michael
