merge-recursive.[ch] have three entry points:
* merge_trees()
* merge_recursive()
* merge_recursive_generic()
merge-ort*.[ch] only has equivalents for the first two. Add an
equivalent for the final entry point, so we can switch callers to
use it and remove merge-recursive.[ch].
While porting it over, finally fix the issue with the label for the
ancestor (used when merge.conflictStyle=diff3 as a conflict label).
merge-recursive.c has traditionally not allowed callers to set that
label, but I have found that problematic for years.
(Side note: This function was initially part of the merge-ort rewrite,
but reviewers questioned the ancestor label funnyness which I was
never really happy with anyway. It resulted in me jettisoning it and
hoping at the time that I would eventually be able to force the existing
callers to use some other API. That worked with `git stash`, as per
874cf2a604 (stash: apply stash using 'merge_ort_nonrecursive()',
2022-05-10), but this API is the most reasonable one for `git am` and
`git merge-recursive`, if we can just allow them some freedom over the
ancestor label.)
The merge_recursive_generic() function did not know whether it was being
invoked by `git stash`, `git merge-recursive`, or `git am`, and the
choice of meaningful ancestor label, when there is a unique ancestor,
varies for these different callers:
* git am: ancestor is a constructed "fake ancestor" that user knows
nothing about and has no access to. (And is different than
the normal thing we mean by a "virtual merge base" which is
the merging of merge bases.)
* git merge-recursive: ancestor might be a tree, but at least it
was one specified by the user (if they invoked
merge-recursive directly)
* git stash: ancestor was the commit serving as the stash base
Thus, using a label like "constructed merge base" (as
merge_recursive_generic() does) presupposes that `git am` is the only
caller; it is incorrect for other callers. This label has thrown me off
more than once. Allow the caller to override when there is a unique
merge base.
Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public
License version 2 (some parts of it are under different licenses,
compatible with the GPLv2). It was originally written by Linus
Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/
including full documentation and Git related tools.
See Documentation/gittutorial.adoc to get started, then see
Documentation/giteveryday.adoc for a useful minimum set of commands, and
Documentation/git-<commandname>.adoc for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
Issues which are security relevant should be disclosed privately to
the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that
list the current status of various development topics to the mailing
list. The discussion following them give a good reference for
project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very
first version. He described the tool as "the stupid content tracker"
and the name as (depending on your mood):
random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
"global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
"goddamn idiotic truckload of sh*t": when it breaks
