Re: Cumulative "git read-tree -m" rejected with overwriting warning

[Junio C Hamano <gitster@pobox.com>]

Marcin Owsiany <marcin@owsiany.pl> writes:

>  "the index file saves and restores with all this information, so you
>  can merge things incrementally,"
>
> which I took to mean that I can read from multiple trees one by one
> before writing the tree.

That "incrementally" refers to "after a three-way merge stops with
conflicts in multiple files, you can start from file A, concentrate
only on that file, resolve it, and then go on to resolve conflicts
in the next file B, continue, until you resolve the conflicts in the
last file Z".  Until you resolve a single tree-way merge fully and
write the results out as a tree, you cannot merge in the next tree.

That is why N-way octopus is internally implemented as a series of
three-way merges.