This patch lets `git range-diff` use the same order as tbdiff.
The idea is simple: for left-to-right readers, it is natural to assume
that the `git range-diff` is performed between an older vs a newer
version of the branch. As such, the user is probably more interested in
the question "where did this come from?" rather than "where did that one
go?".
To that end, we list the commits in the order of the second commit range
("the newer version"), inserting the unmatched commits of the first
commit range as soon as all their predecessors have been shown.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
At this stage, `git range-diff` can determine corresponding commits
of two related commit ranges. This makes use of the recently introduced
implementation of the linear assignment algorithm.
The core of this patch is a straight port of the ideas of tbdiff, the
apparently dormant project at https://github.com/trast/tbdiff.
The output does not at all match `tbdiff`'s output yet, as this patch
really concentrates on getting the patch matching part right.
Note: due to differences in the diff algorithm (`tbdiff` uses the Python
module `difflib`, Git uses its xdiff fork), the cost matrix calculated
by `range-diff` is different (but very similar) to the one calculated
by `tbdiff`. Therefore, it is possible that they find different matching
commits in corner cases (e.g. when a patch was split into two patches of
roughly equal length).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
