It's actually very useful for other things too. Notably, we could do the
combined diff a lot more efficiently with this.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
On Tue, 14 Feb 2006, Linus Torvalds wrote:
>
> Here, btw, is the trivial diff to turn my previous "tree-resolve" into a
> "resolve tree relative to the current branch".
Gaah. It was trivial, and it happened to work fine for my test-case, but
when I started looking at not doing that extremely aggressive subdirectory
merging, that showed a few other issues...
So in case people want to try, here's a third patch. Oh, and it's against
my _original_ path, not incremental to the middle one (ie both patches two
and three are against patch #1, it's not a nice series).
Now I'm really done, and won't be sending out any more patches today.
Sorry for the noise.
Linus
Signed-off-by: Junio C Hamano <junkio@cox.net>
On Tue, 14 Feb 2006, Junio C Hamano wrote:
> Linus Torvalds <torvalds@osdl.org> writes:
>
> > If somebody is interested in making the "lots of filename changes" case go
> > fast, I'd be more than happy to walk them through what they'd need to
> > change. I'm just not horribly motivated to do it myself. Hint, hint.
>
> In case anybody is wondering, I share the same feeling. I
> cannot say I'd be "more than happy to" clean up potential
> breakages during the development of such changes, but if the
> change eventually would help certain use cases, I can be
> persuaded to help debugging such a mess ;-).
Actually, I got interested in seeing how hard this is, and wrote a simple
first cut at doing a tree-optimized merger.
Let me shout a bit first:
THIS IS WORKING CODE, BUT BE CAREFUL: IT'S A TECHNOLOGY DEMONSTRATION
RATHER THAN THE FINAL PRODUCT!
With that out of the way, let me descibe what this does (and then describe
the missing parts).
This is basically a three-way merge that works entirely on the "tree"
level, rather than on the index. A lot of the _concepts_ are the same,
though, and if you're familiar with the results of an index merge, some of
the output will make more sense.
You give it three trees: the base tree (tree 0), and the two branches to
be merged (tree 1 and tree 2 respectively). It will then walk these three
trees, and resolve them as it goes along.
The interesting part is:
- it can resolve whole sub-directories in one go, without actually even
looking recursively at them. A whole subdirectory will resolve the same
way as any individual files will (although that may need some
modification, see later).
- if it has a "content conflict", for subdirectories that means "try to
do a recursive tree merge", while for non-subdirectories it's just a
content conflict and we'll output the stage 1/2/3 information.
- a successful merge will output a single stage 0 ("merged") entry,
potentially for a whole subdirectory.
- it outputs all the resolve information on stdout, so something like the
recursive resolver can pretty easily parse it all.
Now, the caveats:
- we probably need to be more careful about subdirectory resolves. The
trivial case (both branches have the exact same subdirectory) is a
trivial resolve, but the other cases ("branch1 matches base, branch2 is
different" probably can't be silently just resolved to the "branch2"
subdirectory state, since it might involve renames into - or out of -
that subdirectory)
- we do not track the current index file at all, so this does not do the
"check that index matches branch1" logic that the three-way merge in
git-read-tree does. The theory is that we'd do a full three-way merge
(ignoring the index and working directory), and then to update the
working tree, we'd do a two-way "git-read-tree branch1->result"
- I didn't actually make it do all the trivial resolve cases that
git-read-tree does. It's a technology demonstration.
Finally (a more serious caveat):
- doing things through stdout may end up being so expensive that we'd
need to do something else. In particular, it's likely that I should
not actually output the "merge results", but instead output a "merge
results as they _differ_ from branch1"
However, I think this patch is already interesting enough that people who
are interested in merging trees might want to look at it. Please keep in
mind that tech _demo_ part, and in particular, keep in mind the final
"serious caveat" part.
In many ways, the really _interesting_ part of a merge is not the result,
but how it _changes_ the branch we're merging into. That's particularly
important as it should hopefully also mean that the output size for any
reasonable case is minimal (and tracks what we actually need to do to the
current state to create the final result).
The code very much is organized so that doing the result as a "diff
against branch1" should be quite easy/possible. I was actually going to do
it, but I decided that it probably makes the output harder to read. I
dunno.
Anyway, let's think about this kind of approach.. Note how the code itself
is actually quite small and short, although it's prbably pretty "dense".
As an interesting test-case, I'd suggest this merge in the kernel:
git-merge-tree $(git-merge-base 4cbf876 7d2babc) 4cbf876 7d2babc
which resolves beautifully (there are no actual file-level conflicts), and
you can look at the output of that command to start thinking about what
it does.
The interesting part (perhaps) is that timing that command for me shows
that it takes all of 0.004 seconds.. (the git-merge-base thing takes
considerably more ;)
The point is, we _can_ do the actual merge part really really quickly.
Linus
PS. Final note: when I say that it is "WORKING CODE", that is obviously by
my standards. IOW, I tested it once and it gave reasonable results - so it
must be perfect.
Whether it works for anybody else, or indeed for any other test-case, is
not my problem ;)
Signed-off-by: Junio C Hamano <junkio@cox.net>
This adds --date-order to rev-list; it is similar to topo order
in the sense that no parent comes before all of its children,
but otherwise things are still ordered in the commit timestamp
order.
The same flag is also added to show-branch.
Signed-off-by: Junio C Hamano <junkio@cox.net>
If Git is compiled with NO_CURL=YesPlease and one tries to
clone a http repository, git-clone tries to call the curl
binary. This trivial patch prints an error instead in such
situation.
Signed-off-by: Fernando J. Pereda <ferdy@gentoo.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This is in the same spirit as an earlier patch for git-commit.
It does an extra ls-files to avoid complaining when a fully
tracked directory name is given on the command line (otherwise
--others restriction would say the pathspec does not match).
Signed-off-by: Junio C Hamano <junkio@cox.net>
Earlier patch mistakenly used prefix_len when it meant
prefix_offset. The latter is to strip the leading directories
when run from a subdirectory.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This allows you to rewrite history a bit more flexibly, by
separating the other branch name and new branch point. By
default, the new branch point is the same as the tip of the
other branch as before, but you can specify where you graft the
rebased branch onto.
When you have this ancestry graph:
A---B---C topic
/
D---E---F---G master
$ git rebase --onto master~1 master topic
would rewrite the history to look like this:
A'\''--B'\''--C'\'' topic
/
D---E---F---G master
Signed-off-by: Junio C Hamano <junkio@cox.net>
When we refused to switch branches, we incorrectly showed
differences from the branch we would have switched to.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When you say "git commit Documentaiton" to make partial commit
for the files only in that directory, we did not detect that as
a misspelled pathname and attempted to commit index without
change. If nothing matched, there is no harm done, but if the
index gets modified otherwise by having another valid pathspec
or after an explicit update-index, a user will not notice
without paying attention to the "git status" preview.
This introduces --error-unmatch option to ls-files, and uses it
to detect this common user error.
Signed-off-by: Junio C Hamano <junkio@cox.net>
New -r flag for prepending the corresponding Subversion revision
number to each commit message.
Signed-off-by: Karl Hasselström <kha@treskal.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The raw format "git-diff-files -c" to show unmerged state forgot
to initialize the status fields from parents, causing NUL
characters to be emitted.
Signed-off-by: Junio C Hamano <junkio@cox.net>
* master:
Merge some proposed fixes
s/SHELL/SHELL_PATH/ in Makefile
bisect: remove BISECT_NAMES after done.
Documentation: git-ls-files asciidocco.
Documentation: git-commit in 1.2.X series defaults to --include.
Merge branch 'pb/bisect'
When showing a conflicted merge from index stages and working
tree file, we did not fetch the mode from the working tree,
and mistook that as a deleted file. Also if the manual
resolution (or automated resolution by git rerere) ended up
taking either parent's version, we did not show _anything_ for
that path. Either was quite bad and confusing.
Signed-off-by: Junio C Hamano <junkio@cox.net>
With the current Makefile we don't use the shell chosen by the
platform specific defines when we invoke GIT-VERSION-GEN.
Signed-off-by: Fredrik Kuivinen <freku045@student.liu.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
I noticed that we forgot to clean this file and kept it that
way, while trying to help with Andrew's bisect problem.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Since Junio used this in an example, and I've personally tried to use it, I
suppose the option should actually exist.
Signed-off-by: Ryan Anderson <ryan@michonline.com>
The documentation was mistakenly describing the --only semantics to
be default. The 1.2.0 release and its maintenance series 1.2.X will
keep the traditional --include semantics as the default. Clarify the
situation.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This lets a hook to interfere a rebase and help prevent certain
branches from being rebased by mistake. A sample hook to show
how to prevent a topic branch that has already been merged into
publish branch.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This changes the "git commit paths..." to default to --only
semantics from traditional --include semantics, as agreed on the
list.
Signed-off-by: Junio C Hamano <junkio@cox.net>
git-bisect reset without an argument would return to master even
if the bisecting started at a non-master branch. This patch makes
it save the original branch name to .git/head-name and restore it
afterwards.
This is also compatible with Cogito and cg-seek, so cg-status will
show that we are seeked on the bisect branch and cg-reset will
properly restore the original branch.
git-bisect start will refuse to work if it is not on a bisect but
.git/head-name exists; this is to protect against conflicts with
other seeking tools.
Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Earlier, when we switched a branch we used diff-files to show
paths that are dirty in the working tree. But we allow switching
branches with updated index ("read-tree -m -u $old $new" works that
way), and only showing paths that have differences in the working
tree but not paths that are different in index was confusing.
This shows both as modified from the top commit of the branch we
just have switched to.
Signed-off-by: Junio C Hamano <junkio@cox.net>
