Re: [PATCHv3 5/6] fast-export: Fix output order of D/F changes

newren@gmail.com writes:

From: Elijah Newren <redacted>

The fast-import stream format requires incremental changes which take place
immediately, meaning that for D->F conversions all files below the relevant
directory must be deleted before the resulting file of the same name is
created.  Reversing the order can result in fast-import silently deleting
the file right after creating it, resulting in the file missing from the
resulting repository.

We correct the order by instructing the diff_tree machinery to compare
entries using df_name_compare instead of base_name_compare.

I am not so sure about this one.

You can be walking two trees, one of which has "b-1" (blob), "b-2" (blob)
and then "b" (tree), while the other one has "b" (blob), "b-1" (blob) and
then "b-2" (blob).  The patch tells the machinery that "b" (tree) sorts
just like "b" (blob) only during comparison, but the actual data stream it
is walking is sorted differently.  Without some form of lookahead, can you
reliably "correct the order"?