rebase-helper --make-script: introduce a flag to rebase merges
The sequencer just learned new commands intended to recreate branch
structure (similar in spirit to --preserve-merges, but with a
substantially less-broken design).
Let's allow the rebase--helper to generate todo lists making use of
these commands, triggered by the new --rebase-merges option. For a
commit topology like this (where the HEAD points to C):
- A - B - C
\ /
D
the generated todo list would look like this:
# branch D
pick 0123 A
label branch-point
pick 1234 D
label D
reset branch-point
pick 2345 B
merge -C 3456 D # C
To keep things simple, we first only implement support for merge commits
with exactly two parents, leaving support for octopus merges to a later
patch series.
All merge-rebasing todo lists start with a hard-coded `label onto` line.
This makes it convenient to refer later on to the revision onto which
everything is rebased, e.g. as starting point for branches other than
the very first one.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>