Re: What's cooking in git.git (Sep 2018, #04; Thu, 20)

["René Scharfe" <l.s.r@web.de>]

Am 01.10.2018 um 22:12 schrieb Jeff King:
> On Mon, Oct 01, 2018 at 09:16:07PM +0200, René Scharfe wrote:
> 
>> Am 21.09.2018 um 07:22 schrieb Junio C Hamano:
>>> * cc/delta-islands (2018-08-16) 7 commits
>> [...]
>>> * jk/pack-delta-reuse-with-bitmap (2018-08-21) 6 commits
>>
>> Not sure if it's the interaction of the two topics or if only one of
>> them is to blame, but the result of the merge can dereference a NULL
>> pointer.  Found using Clang's UBSan and t5310.
>>
>> Here's a patch that avoids the issue, but I don't know if it's the
>> right thing to do -- should we rather treat a non-existing base as
>> "not from the same island" instead?
>>
>> And it's certainly ugly -- that condition is complicated enough
>> already.  Splitting it up in a nice way would probably help, but how?
> 
> Perhaps like in 2fa233a554 (pack-objects: handle island check for
> "external" delta base, 2018-09-18)?

Perhaps indeed. ;-)  That patch looks exactly like the fix I wished for,
and then some.  I'm just not fully sure about the added branch for the
combination of the two features, because I don't know either of them in
depth.

René