Re: Null deref in recursive merge in df73af5f667a479764d2b2195cb0cb60b0b89e3d

[Fredrik Kuivinen <frekui@gmail.com>]

On Thu, Jul 30, 2009 at 9:45 AM, Junio C Hamano<gitster@pobox.com> wrote:
> Junio C Hamano <gitster@pobox.com> writes:
>
>> The codepath saw that one branch renamed dev-ubuntu/ stuff to dev/ at that
>> "unmerged" path, while the other branch added something else to the same
>> path, and decided to add that at an alternative path, and the intent of
>> that is so that it can safely resolve the "renamed" side to its final
>> destination.  The added update_file() call is about finishing that
>> conflict resolution the code forgets to do.
>
> By the way, (I am CC'ing Fredrik, the author of the merge-recursive.py,
> the original implementation, even though I haven't seen him around here
> for a long time. Two "thieves" are also CC'ed), I think the way recursive
> strategy tries to handle rename/add and rename/rename conflicts by coming
> up with a temporary pathname is fundamentally wrong.

It was a long time ago I looked at the merge stuff (or any git code in
fact) so I
may have forgotten some things. However, as far as I can see your analysis is
correct and the temporary pathname stuff can be avoided when the conflicts
only involve files (and no directories). As you wrote, for D/F
conflicts one need
the temporary pathnames in order to build a tree which is used in the virtual
ancestor.

[Nice analysis of when temporary pathnames are needed and when they are not
needed snipped.]

- Fredrik

PS. I am sorry for the late reply.