Re: [PATCH] read-tree --aggressive

Junio C Hamano [off-list ref] writes:

This patch would not help recursive strategy, though.  Calling
read-tree with --aggressive flag essentially disables the
benefit we would expect to get from it -- rename detection.

I think we could fairly easily tweak this by trying at least
half of the rename detection inside read-tree.  That would make
it usable by merge-recursive as well.

Instead of doing "aggressive" in the threeway_merge function
first, we can process the stages without it in the first pass,
and run an equivalent of diff-stages -M internally between stage
#2 and stage #3, and keep the matched paths unmerged (we need to
mark these paths somehow).  After that, we can do "aggressive"
collapsing to reduce the amount of trivial merges that recursive
does not have to look at for renaming merges.

If we are ambitious, we could go further.  We could actually
move the stages around after running the rename detection diff
between stages #2 and #3, along with working tree files as
needed.  Then merge-resolve would be able to do the renaming
merge similar to merge-recursive.