Commit Graph

441 Commits

Author SHA1 Message Date
Junio C Hamano
8eef8e09ce Makefile: many programs now depend on xdiff/lib.a having been built.
The dependency was not properly updated when we added this
library, breaking parallel build with $(MAKE) -j.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-31 16:23:46 -08:00
Junio C Hamano
1b0c7174a1 tree/diff header cleanup.
Introduce tree-walk.[ch] and move "struct tree_desc" and
associated functions from various places.

Rename DIFF_FILE_CANON_MODE(mode) macro to canon_mode(mode) and
move it to cache.h.  This macro returns the canonicalized
st_mode value in the host byte order for files, symlinks and
directories -- to be compared with a tree_desc entry.
create_ce_mode(mode) in cache.h is similar but is intended to be
used for index entries (so it does not work for directories) and
returns the value in the network byte order.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-29 23:54:13 -08:00
Jason Riedy
9c48666aa0 Add ALL_LDFLAGS to the git target.
For some reason, I need ALL_LDFLAGS in the git target only on
AIX.  Once it builds, only one test "fails" on AIX 5.1 with
1.3.0.rc1, t5500-fetch-pack.sh, but it looks like it's some
odd tool problem in the tester + my setup and not a real bug.

Signed-off-by: Jason Riedy <ejr@cs.berkeley.edu>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-27 17:55:20 -08:00
Junio C Hamano
ac93bfc3b6 Merge branch 'lt/diffgen' into next
* lt/diffgen:
  add clean and ignore rules for xdiff/
  Remove dependency on a file named "-lz"
2006-03-26 23:44:28 -08:00
Junio C Hamano
3467fec516 add clean and ignore rules for xdiff/
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-26 23:41:22 -08:00
Johannes Schindelin
54c261f90f Remove dependency on a file named "-lz"
By changing the dependency "$(LIB_H)" to "$(LIBS)", at least one version
of make thought that a file named "-lz" would be needed.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-26 19:07:08 -08:00
Junio C Hamano
9acf322d69 Merge branch 'lt/diffgen' into next
* lt/diffgen:
  built-in diff: minimum tweaks
  builtin-diff: \No newline at end of file.
  Use a *real* built-in diff generator
2006-03-25 17:44:01 -08:00
Linus Torvalds
3443546f6e Use a *real* built-in diff generator
This uses a simplified libxdiff setup to generate unified diffs _without_
doing  fork/execve of GNU "diff".

This has several huge advantages, for example:

Before:

	[torvalds@g5 linux]$ time git diff v2.6.16.. > /dev/null

	real    0m24.818s
	user    0m13.332s
	sys     0m8.664s

After:

	[torvalds@g5 linux]$ time git diff v2.6.16.. > /dev/null

	real    0m4.563s
	user    0m2.944s
	sys     0m1.580s

and the fact that this should be a lot more portable (ie we can ignore all
the issues with doing fork/execve under Windows).

Perhaps even more importantly, this allows us to do diffs without actually
ever writing out the git file contents to a temporary file (and without
any of the shell quoting issues on filenames etc etc).

NOTE! THIS PATCH DOES NOT DO THAT OPTIMIZATION YET! I was lazy, and the
current "diff-core" code actually will always write the temp-files,
because it used to be something that you simply had to do. So this current
one actually writes a temp-file like before, and then reads it into memory
again just to do the diff. Stupid.

But if this basic infrastructure is accepted, we can start switching over
diff-core to not write temp-files, which should speed things up even
further, especially when doing big tree-to-tree diffs.

Now, in the interest of full disclosure, I should also point out a few
downsides:

 - the libxdiff algorithm is different, and I bet GNU diff has gotten a
   lot more testing. And the thing is, generating a diff is not an exact
   science - you can get two different diffs (and you will), and they can
   both be perfectly valid. So it's not possible to "validate" the
   libxdiff output by just comparing it against GNU diff.

 - GNU diff does some nice eye-candy, like trying to figure out what the
   last function was, and adding that information to the "@@ .." line.
   libxdiff doesn't do that.

 - The libxdiff thing has some known deficiencies. In particular, it gets
   the "\No newline at end of file" case wrong. So this is currently for
   the experimental branch only. I hope Davide will help fix it.

That said, I think the huge performance advantage, and the fact that it
integrates better is definitely worth it. But it should go into a
development branch at least due to the missing newline issue.

Technical note: this is based on libxdiff-0.17, but I did some surgery to
get rid of the extraneous fat - stuff that git doesn't need, and seriously
cutting down on mmfile_t, which had much more capabilities than the diff
algorithm either needed or used. In this version, "mmfile_t" is just a
trivial <pointer,length> tuple.

That said, I tried to keep the differences to simple removals, so that you
can do a diff between this and the libxdiff origin, and you'll basically
see just things getting deleted. Even the mmfile_t simplifications are
left in a state where the diffs should be readable.

Apologies to Davide, whom I'd love to get feedback on this all from (I
wrote my own "fill_mmfile()" for the new simpler mmfile_t format: the old
complex format had a helper function for that, but I did my surgery with
the goal in mind that eventually we _should_ just do

	mmfile_t mf;

	buf = read_sha1_file(sha1, type, &size);
	mf->ptr = buf;
	mf->size = size;
	.. use "mf" directly ..

which was really a nightmare with the old "helpful" mmfile_t, and really
is that easy with the new cut-down interfaces).

[ Btw, as any hawk-eye can see from the diff, this was actually generated
  with itself, so it is "self-hosting". That's about all the testing it
  has gotten, along with the above kernel diff, which eye-balls correctly,
  but shows the newline issue when you double-check it with "git-apply" ]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-25 16:49:58 -08:00
Junio C Hamano
b7986ce884 Merge branch 'master' into next
* master:
  Makefile: Add TAGS and tags targets
  ls-files: Don't require exclude files to end with a newline.
2006-03-18 14:58:20 -08:00
Fredrik Kuivinen
f81e7c626f Makefile: Add TAGS and tags targets
Signed-off-by: Fredrik Kuivinen <freku045@student.liu.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-18 14:01:46 -08:00
Junio C Hamano
c301a0d2cf Merge branch 'fk/blame' into next
* fk/blame:
  blame: Rename detection (take 2)
  rev-lib: Make it easy to do rename tracking (take 2)
  Make it possible to not clobber object.util in sort_in_topological_order (take 2)
  Add git-imap-send, derived from isync 1.0.1.
  repack: prune loose objects when -d is given
  try_to_simplify_commit(): do not skip inspecting tree change at boundary.
  Fix t1200 test for breakage caused by removal of full-stop at the end of fast-forward message.
  Describe how to add extra mail header lines in mail generated by git-format-patch.
  Document the --attach flag.
  allow double click on current HEAD id after git-pull
2006-03-10 22:32:59 -08:00
Mike McCormack
f2561fda36 Add git-imap-send, derived from isync 1.0.1.
git-imap-send drops a patch series generated by git-format-patch into an
IMAP folder. This allows patch submitters to send patches through their
own mail program.

git-imap-send uses the following values from the GIT repository
configuration:

The target IMAP folder:

[imap]
         Folder = "INBOX.Drafts"

A command to open an ssh tunnel to the imap mail server.

[imap]
         Tunnel = "ssh -q user@imap.server.com /usr/bin/imapd ./Maildir
2> /dev/null"

[imap]
         Host = imap.server.com
         User = bob
         Password = pwd
         Port = 143
2006-03-10 22:09:24 -08:00
Junio C Hamano
b8cfe290a8 Merge branch 'jc/fsck' into next
* jc/fsck:
  fsck-objects: Remove --standalone
  refs.c::do_for_each_ref(): Finish error message lines with "\n"
  Nicer output from 'git'
  Use #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  Remove trailing dot after short description
  Fix some inconsistencies in the docs
  contrib/git-svn: fix a harmless warning on rebuild (with old repos)
  contrib/git-svn: remove the --no-stop-on-copy flag
  contrib/git-svn: fix svn compat and fetch args
  Don't recurse into parents marked uninteresting.
  diff-delta: bound hash list length to avoid O(m*n) behavior
  test-delta needs zlib to compile
  git-fmt-merge-msg cleanup
2006-03-09 13:10:50 -08:00
Fredrik Kuivinen
a87cd02ce0 Nicer output from 'git'
[jc: with suggestions by Jan-Benedict Glaw]

Signed-off-by: Fredrik Kuivinen <freku045@student.liu.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-09 12:03:14 -08:00
Nicolas Pitre
3d99a7f4fa test-delta needs zlib to compile
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-09 01:35:07 -08:00
Junio C Hamano
2acc35b087 Merge branch 'master' into next
* master:
  repo-config: give value_ a sane default so regexec won't segfault
  Update http-push functionality
  cvsimport: Remove master-updating code
2006-03-07 17:07:40 -08:00
Nick Hengeveld
aa1dbc9897 Update http-push functionality
This brings http-push functionality more in line with the ssh/git version,
by borrowing bits from send-pack and rev-list to process refspecs and
revision history in more standard ways.  Also, the status of remote objects
is determined using PROPFIND requests for the object directory rather than
HEAD requests for each object - while it may be less efficient for small
numbers of objects, this approach is able to get the status of all remote
loose objects in a maximum of 256 requests.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-07 17:03:21 -08:00
Junio C Hamano
a0fb95e319 blame: avoid -lm by not using log().
... as suggested on the list.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-05 16:02:44 -08:00
Fredrik Kuivinen
ea4c7f9bf6 git-blame: Make the output human readable
The default output mode is slightly different from git-annotate's.
However, git-annotate's output mode can be obtained by using the
'-c' flag.

Signed-off-by: Fredrik Kuivinen <freku045@student.liu.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-05 14:49:58 -08:00
Junio C Hamano
f5948cfe67 count-delta: no need for this anymore.
This is a companion patch to e29e1147e4
which made diffcore similarity estimator independent from the packfile
deltifier.  There is no reason for us to be counting the xdelta anymore.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-04 13:26:36 -08:00
Junio C Hamano
f2fea68a0f Merge branch 'fk/blame'
* fk/blame:
  git-blame, take 2
  Merge part of 'lt/rev-list' into 'fk/blame'
  Add git-blame, a tool for assigning blame.
2006-03-04 13:22:01 -08:00
Junio C Hamano
21dbe12c76 Merge branch 'lt/rev-list'
* lt/rev-list:
  setup_revisions(): handle -n<n> and -<n> internally.
  git-log (internal): more options.
  git-log (internal): add approxidate.
  Rip out merge-order and make "git log <paths>..." work again.
  Tie it all together: "git log"
  Introduce trivial new pager.c helper infrastructure
  git-rev-list libification: rev-list walking
  Splitting rev-list into revisions lib, end of beginning.
  rev-list split: minimum fixup.
  First cut at libifying revlist generation
2006-03-04 13:21:17 -08:00
Junio C Hamano
c40610422e Merge part of 'lt/rev-list' into 'fk/blame'
Now blame will depend on the new revision walker infrastructure,
we need to make it depend on earlier parts of Linus' rev-list
topic branch, hence this merge.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-02 15:10:05 -08:00
Linus Torvalds
765ac8ec46 Rip out merge-order and make "git log <paths>..." work again.
Well, assuming breaking --merge-order is fine, here's a patch (on top of
the other ones) that makes

	git log <filename>

actually work, as far as I can tell.

I didn't add the logic for --before/--after flags, but that should be
pretty trivial, and is independent of this anyway.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-01 01:45:50 -08:00
Junio C Hamano
65416758cd diffcore-rename: split out the delta counting code.
This is to rework diffcore break/rename/copy detection code
so that it does not affected when deltifier code gets improved.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-28 20:20:04 -08:00
Linus Torvalds
70b006b971 Tie it all together: "git log"
This is what the previous diffs all built up to.

We can do "git log" as a trivial small helper function inside git.c,
because the infrastructure is all there for us to use as a library.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-28 14:49:34 -08:00
Linus Torvalds
f67b45f862 Introduce trivial new pager.c helper infrastructure
This introduces the new function

	void setup_pager(void);

to set up output to be written through a pager applocation.

All in preparation for doing the simple scripts in C.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-28 14:49:32 -08:00
Shawn Pearce
e3601e8bb7 Darwin: Ignore missing /sw/lib
When on Darwin platforms don't include Fink or DarwinPorts
into the link path unless the related library directory
is actually present.  The linker on MacOS 10.4 complains
if it is given a directory which does not exist.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-28 11:02:13 -08:00
Linus Torvalds
ae563542bf First cut at libifying revlist generation
This really just splits things up partially, and creates the
interface to set things up by parsing the command line.

No real code changes so far, although the parsing of filenames is a bit
stricter. In particular, if there is a "--", then we do not accept any
filenames before it, and if there isn't any "--", then we check that _all_
paths listed are valid, not just the first one.

The new argument parsing automatically also gives us "--default" and
"--not" handling as in git-rev-parse.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-26 15:33:27 -08:00
Junio C Hamano
43f72af1bc Build and install git-mailinfo.
The merge 712b1dd389 was done
incorrectly, and lost this program from Makefile.

Big thanks go to Tony Luck for noticing it, and Linus for
diagnosing it.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-24 16:16:10 -08:00
Junio C Hamano
98214e96be Merge branch 'ml/cvs'
* ml/cvs:
  Introducing git-cvsserver -- a CVS emulator for git.
2006-02-22 19:20:55 -08:00
Junio C Hamano
ab8c9fe256 Merge branch 'ra/anno'
* ra/anno:
  Use Ryan's git-annotate instead of jsannotate
  Add git-annotate, a tool for assigning blame.
2006-02-22 19:20:08 -08:00
Carl Worth
d4a1cab541 Add new git-rm command with documentation
This adds a git-rm command which provides convenience similar to
git-add, (and a bit more since it takes care of the rm as well if
given -f).

Like git-add, git-rm expands the given path names through
git-ls-files. This means it only acts on files listed in the
index. And it does act recursively on directories by default, (no -r
needed as in the case of rm itself). When it recurses, it does not
remove empty directories that are left behind.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-22 17:10:42 -08:00
Martin Langhoff
3fda8c4cc7 Introducing git-cvsserver -- a CVS emulator for git.
git-cvsserver is highly functional. However, not all methods are implemented,
and for those methods that are implemented, not all switches are implemented.
All the common read operations are implemented, and add/remove/commit are
supported.

Testing has been done using both the CLI CVS client, and the Eclipse CVS
plugin. Most functionality works fine with both of these clients.

Currently git-cvsserver only works over SSH connections, see the
Documentation for more details on how to configure your client. It
does not support pserver for anonymous access but it should not be
hard to implement. Anonymous access will need tighter input validation.

In our very informal tests, it seems to be significantly faster than a real
CVS server.

This utility depends on a version of git-cvsannotate that supports -S and on
DBD::SQLite.

Licensed under GPLv2. Copyright The Open University UK.

Authors: Martyn Smith <martyn@catalyst.net.nz>
         Martin Langhoff <martin@catalyst.net.nz>

Signed-off-by: Martin Langhoff <martin@catalyst.net.nz>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-22 02:17:07 -08:00
Junio C Hamano
712b1dd389 Merge branch 'js/portable'
* js/portable:
  Fix "gmake -j"
  Really honour NO_PYTHON
  avoid makefile override warning
  Fixes for ancient versions of GNU make
2006-02-21 22:28:40 -08:00
Johannes Schindelin
b992933853 Fix "gmake -j"
In my attempt to port git to IRIX, I broke it. Sorry.

Signed-off-by: Johannes E. Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-21 16:48:10 -08:00
Paul Jakma
e15f545155 Makefile tweaks: Solaris 9+ dont need iconv / move up uname variables
- Solaris 9 and up do not need -liconv, so NEEDS_LIBICONV should be set
   only for S8.
- Move the declaration of the uname variables to early in the Makefile
   so they can be referenced by prefix and gitexecdir variables.
- gitexecdir defaults to being same as bindir, it might as well reference
   that variable.

[jc: corrupt patch, sneakily tried to remove inclusion of GIT-VERSION-FILE
 I do not know why I am applying this...]

Signed-off-by: Paul Jakma <paul@quagga.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-21 00:55:00 -08:00
Fredrik Kuivinen
cbfb73d73f Add git-blame, a tool for assigning blame.
I have also been working on a blame program. The algorithm is pretty
much the one described by Junio in his blame.perl. My variant doesn't
handle renames, but it shouldn't be too hard to add that. The output
is minimal, just the line number followed by the commit SHA1.

An interesting observation is that the output from my git-blame and
your git-annotate doesn't match on all files in the git
repository. One example where several lines differ is read-cache.c. I
haven't investigated it further to find out which one is correct.

The code should be considered as a work in progress. It certainly has
a couple of rough edges. The output looks fairly sane on the few files
I have tested it on, but it wouldn't be too surprising if it gets some
cases wrong.

[jc: adding it to pu for wider comments. I did minimum
whitespace fixups but it still needs an indent run and
-Wdeclaration-after-statement fixups.]

Signed-off-by: Fredrik Kuivinen <freku045@student.liu.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-21 00:54:34 -08:00
Junio C Hamano
6643688867 Merge part of jc/portable branch 2006-02-21 00:52:18 -08:00
Junio C Hamano
83f50539a9 git-mktree: reverse of git-ls-tree.
This reads data in the format a (non recursive) ls-tree outputs
and writes a tree object to the object database.  The created
tree object name is output to the standard output.

For convenience, the input data does not need to be sorted; the
command sorts the input lines internally.

By request from Tommi Virtanen.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-21 00:50:05 -08:00
Junio C Hamano
8cf828b43c Merge branch 'lt/merge-tree'
* lt/merge-tree:
  git-merge-tree: generalize the "traverse <n> trees in sync" functionality
  Handling large files with GIT
  Handling large files with GIT
2006-02-21 00:49:38 -08:00
Ryan Anderson
c65e898754 Add git-annotate, a tool for assigning blame.
Signed-off-by: Ryan Anderson <ryan@michonline.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-20 13:35:42 -08:00
Johannes Schindelin
a348ab702a Really honour NO_PYTHON
Do not even test for subprocess (trying to execute python).

Signed-off-by: Johannes E. Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-19 16:55:38 -08:00
Johannes Schindelin
2a3763ef3d avoid makefile override warning
Signed-off-by: Johannes E. Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-19 16:55:38 -08:00
Johannes Schindelin
39c015c556 Fixes for ancient versions of GNU make
Some versions of GNU make do not understand $(call), and have problems to
interpret rules like this:

some_target: CFLAGS += -Dsome=defs

[jc: simplified substitution a bit. ]

Signed-off-by: Johannes E. Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-18 23:17:01 -08:00
Johannes Schindelin
abb7c7b31c Optionally work without python
In some setups (notably server setups) you do not need that dependency.
Gracefully handle the absence of python when NO_PYTHON is defined.

Signed-off-by: Johannes E. Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-18 23:16:09 -08:00
Johannes Schindelin
289c4b36e3 Support Irix
Signed-off-by: Johannes E. Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-17 16:32:43 -08:00
Johannes Schindelin
5b5d4d9e1b Optionally support old diffs
Some versions of diff do not correctly detect a missing new-line at the end
of the file under certain circumstances.

When defining NO_ACCURATE_DIFF, work around this bug.

Signed-off-by: Johannes E. Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-17 16:32:41 -08:00
Fernando J. Pereda
b6e56eca8a Allow building Git in systems without iconv
Systems using some uClibc versions do not properly support
iconv stuff. This patch allows Git to be built on those
systems by passing NO_ICONV=YesPlease to make. The only
drawback is mailinfo won't do charset conversion in those
systems.

Signed-off-by: Fernando J. Pereda <ferdy@gentoo.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-16 01:42:58 -08:00
Linus Torvalds
492e0759bf Handling large files with GIT
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>
2006-02-15 23:35:40 -08:00