Re: Memory corruption when rebasing with git version 1.8.1.5 on arch

Jeff King [off-list ref] writes:

and so on. I haven't quite figured out what is going on. It looks like
we call update_pre_post_images with postlen==0, which causes it to just
write the fixed postimage into the existing buffer. But of course the
fixed version is bigger, because we are expanding the tabs into 8
spaces (but it _doesn't_ break if each line starts with only one tab,
which confuses me).

I used to be intimately familiar with the update_pre_post_images()
function, but the version after 86c91f91794c (git apply: option to
ignore whitespace differences, 2009-08-04), I won't vouch for it
doing anything sensible.  We recently had to do 5de7166d46d2
(apply.c:update_pre_post_images(): the preimage can be truncated,
2012-10-12) to fix one of its corner cases but I would not be
surprised if there are other cases the function gets it all wrong.

I'd come back to the topic after I finish other tasks on my plate,
so if somebody is inclined please go ahead digging this a bit
further; I won't have much head start to begin with in this code
X-<.