Commit Graph

18429 Commits

Author SHA1 Message Date
Junio C Hamano
1c12b38601 Merge branch 'jc/author-nickname'
* jc/author-nickname:
  git commit --author=$name: look $name up in existing commits
2008-09-02 17:45:28 -07:00
Junio C Hamano
14e8607c41 Merge branch 'dp/pid-uintmax'
* dp/pid-uintmax:
  cast pid_t's to uintmax_t to improve portability
2008-09-02 17:45:25 -07:00
Giuseppe Bilotta
4afbaefffa gitweb: ref markers link to named shortlogs
This patch turns ref markers for tags and heads into links to
appropriate views for the ref name, depending on current context.

For annotated tags, we link to the tag view, unless that's the current
view, in which case we switch to shortlog. For other refs, we prefer the
current view if it's history or (short)log, and default to shortlog
otherwise.

Appropriate changes are made in the CSS to prevent ref markers from
being annoyingly blue and underlined, unless hovered. A visual
indication of the target view difference is also implemented by making
annotated tags show up in italic.

Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Acked-by: Petr Baudis <pasky@suse.cz>
Acked-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-02 17:10:37 -07:00
Junio C Hamano
106db883b7 Merge branch 'maint'
* maint:
  Makefile: add merge_recursive.h to LIB_H
  Improve documentation for --dirstat diff option
  Bring local clone's origin URL in line with that of a remote clone
  Documentation: minor cleanup in a use case in 'git stash' manual
  Documentation: fix disappeared lines in 'git stash' manpage
  Documentation: fix reference to a for-each-ref option
2008-09-02 17:10:08 -07:00
Nicolas Pitre
5f020f7202 t5300: improve SHA1 collision test
Make sure the reason for the command failure is actually due to
the detection of SHA1 collision.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-02 17:05:56 -07:00
Nicolas Pitre
eede9f42b5 pack-objects: don't include missing preferred base objects
This improves commit 6d6f9cddbe a bit by simply not including missing
bases in the list of objects to process at all.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-02 17:05:54 -07:00
Nicolas Pitre
a8032d1224 sha1write: don't copy full sized buffers
No need to memcpy() source buffer data when we might just process the
data in place instead of accumulating it into a separate buffer.
This is the case when a whole buffer would have been copied, summed,
written out and then discarded right away.

Also move the CRC32 processing within the loop so the data is more likely
to remain in the L1 CPU cache between the CRC32 sum, SHA1 sum and the
write call.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-02 17:05:47 -07:00
Junio C Hamano
59d94bc9c8 Merge branch 'np/maint-safer-pack' into np/pack
* np/maint-safer-pack:
  fixup_pack_header_footer(): use nicely aligned buffer sizes
  index-pack: use fixup_pack_header_footer()'s validation mode
  pack-objects: use fixup_pack_header_footer()'s validation mode
  improve reliability of fixup_pack_header_footer()
  pack-objects: improve returned information from write_one()
2008-09-02 17:05:44 -07:00
Miklos Vajna
db3a95459c Makefile: add merge_recursive.h to LIB_H
When modifying merge-recursive.h, for example builtin-merge-recursive.c
have to be recompiled which was not true till now, causing various
runtime errors using an incremental build.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-02 17:03:51 -07:00
Miklos Vajna
6eb1b43793 cherry-pick/revert: make direct internal call to merge_tree()
Refactored merge-recursive interface may still not be ideal but it already
allows us to make a direct call to merge_tree().

One regression is that the status message is lost as there is no way to
flush them from outside the refactored library code yet.

[jc: initial version by Miklos, with moderate amount of fixup by me]

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-02 17:03:01 -07:00
Heikki Orsila
62e00b0a9a Improve documentation for --dirstat diff option
Signed-off-by: Heikki Orsila <heikki.orsila@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-01 23:48:45 -07:00
Johan Herland
86521acaca Bring local clone's origin URL in line with that of a remote clone
On a local clone, "git clone" would use the fully DWIMmed path as the origin
URL in the resulting repo. This was slightly inconsistent with the case of a
remote clone where the _given_ URL was used as the origin URL (because the
DWIMming was done remotely, and was therefore not available to "git clone").

This behaviour caused problems when cloning a local non-bare repo with
relative submodule URLs, because these submodule URLs would then be resolved
against the DWIMmed URL (e.g. "/repo/.git") instead of the given URL (e.g.
"/repo").

This patch teaches "git clone" to use the _given_ URL - instead of the
DWIMmed path - as the origin URL. This causes relative submodule URLs to be
resolved correctly, as long the _given_ URL indicates the correct directory
against which the submodule URLs should be resolved.

The patch also updates a testcase that contained the old-style origin URLs.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-01 23:27:39 -07:00
SZEDER Gábor
f733c70941 Documentation: minor cleanup in a use case in 'git stash' manual
There is no need to explicitly pass the file to be committed to 'git
commit', because it's contents is already in the index.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-01 22:02:11 -07:00
SZEDER Gábor
9da6f0fff2 Documentation: fix disappeared lines in 'git stash' manpage
Asciidoc removes lines starting with a dot when creating manpages.
Since those lines were comments in use case examples showing shell
commands, preceed those lines with a hash sign.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-01 22:01:33 -07:00
SZEDER Gábor
d4040e0a17 Documentation: fix reference to a for-each-ref option
... to match the synopsis section

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-09-01 21:58:22 -07:00
Shawn O. Pearce
961a628fdd Merge branch 'maint'
* maint:
  git-gui: Fix string escaping in po2msg.sh
  git gui: show diffs with a minimum of 1 context line

Conflicts:
	lib/option.tcl
2008-09-01 15:39:56 -07:00
Alexander Gavrilov
9dc3793166 git-gui: Fix string escaping in po2msg.sh
Escape '$', because otherwise git-gui crashes while
trying to load malformed Japanese localization strings.

Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-09-01 15:39:11 -07:00
Clemens Buchacher
55ba8a3474 git gui: show diffs with a minimum of 1 context line
Staging hunks without context does not work, because line number
information would have to be recomputed for individual hunks.

Since it is already possible to stage individual lines using
'Stage Line for Commit', zero context diffs are not really
necessary for git gui.

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-09-01 12:45:46 -07:00
Junio C Hamano
70a3f89733 git-merge documentation: describe how conflict is presented
We took it granted that everybody knows how to read the RCS merge style
conflicts, and did not give illustrations in the documentation.  Now we
are introducing an alternative output style, it is time to document this.

The lack of illustration has been bugging me for a long time.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 20:36:32 -07:00
Junio C Hamano
eac5a40151 checkout --conflict=<style>: recreate merge in a non-default style
This new option does essentially the same thing as -m option when checking
unmerged paths out of the index, but it uses the specified style instead
of configured merge.conflictstyle.

Setting "merge.conflictstyle" to "diff3" is usually less useful than using
the default "merge" style, because the latter allows a conflict that
results by both sides changing the same region in a very similar way to
get simplified substancially by reducing the common lines.  However, when
one side removed a group of lines (perhaps a function was moved to some
other file) while the other side modified it, the default "merge" style
does not give any clue as to why the hunk is left conflicting.  You would
need the original to understand what is going on.

The recommended use would be not to set merge.conflictstyle variable so
that you would usually use the default "merge" style conflict, and when
the result in a path in a particular merge is too hard to understand, use
"git checkout --conflict=diff3 $path" to check it out with the original to
review what is going on.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 20:09:21 -07:00
Junio C Hamano
e910ce30e4 Merge branch 'tr/rev-list-docs' into tr/filter-branch
This prepares the necessary parts to merge filter-branch
fix based on simplify-merges to master.
2008-08-31 17:04:56 -07:00
David Soria Parra
85e7283069 cast pid_t's to uintmax_t to improve portability
Some systems (like e.g. OpenSolaris) define pid_t as long,
therefore all our sprintf that use %i/%d cause a compiler warning
beacuse of the implicit long->int cast. To make sure that
we fit the limits, we display pids as PRIuMAX and cast them explicitly
to uintmax_t.

Signed-off-by: David Soria Parra <dsp@php.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 16:56:22 -07:00
Junio C Hamano
7f314565fe Merge branch 'maint'
* maint:
  Document sendemail.envelopesender configuration
  Document clarification: gitmodules, gitattributes
  config.txt: Add missing colons after option name
2008-08-31 16:52:53 -07:00
Thomas Rast
9d13dec549 t6013: replace use of 'tac' with equivalent Perl
'tac' is not available everywhere, so substitute the equivalent Perl
code 'print reverse <>'.  Noticed by Brian Gernhardt.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 16:34:11 -07:00
Ask Bjørn Hansen
1487743687 Document sendemail.envelopesender configuration
Signed-off-by: Ask Bjørn Hansen <ask@develooper.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 16:32:07 -07:00
Gustaf Hendeby
e5b5c1d2cf Document clarification: gitmodules, gitattributes
The SYNOPSIS section of gitattibutes and gitmodule fail to clearly
specify the name of the in tree files used.  This patch brings in the
initial `.' and the fact that the `.gitmodules' file should reside at
the top-level of the working tree.

Signed-off-by: Gustaf Hendeby <hendeby@isy.liu.se>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 16:31:58 -07:00
Junio C Hamano
394258190c git-add --intent-to-add (-N)
This adds "--intent-to-add" option to "git add".  This is to let the
system know that you will tell it the final contents to be staged later,
iow, just be aware of the presense of the path with the type of the blob
for now.  It is implemented by staging an empty blob as the content.

With this sequence:

    $ git reset --hard
    $ edit newfile
    $ git add -N newfile
    $ edit newfile oldfile
    $ git diff

the diff will show all changes relative to the current commit.  Then you
can do:

    $ git commit -a ;# commit everything

or

    $ git commit oldfile ;# only oldfile, newfile not yet added

to pretend you are working with an index-free system like CVS.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 16:22:05 -07:00
Alex Riesen
f0e90716d4 Add help.autocorrect to enable/disable autocorrecting
It is off(0) by default, to avoid scaring people unless they asked to.
If set to a non-0 value, wait for that amount of deciseconds before
running the corrected command.

Suggested by Junio, so he has a chance to hit Ctrl-C.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 10:15:13 -07:00
Johannes Schindelin
8af84dadb1 git wrapper: DWIM mistyped commands
This patch introduces a modified Damerau-Levenshtein algorithm into
Git's code base, and uses it with the following penalties to show some
similar commands when an unknown command was encountered:

	swap = 0, insertion = 1, substitution = 2, deletion = 4

A typical output would now look like this:

	$ git sm
	git: 'sm' is not a git-command. See 'git --help'.

	Did you mean one of these?
		am
		rm

The cut-off is at similarity rating 6, which was empirically determined
to give sensible results.

As a convenience, if there is only one candidate, Git continues under
the assumption that the user mistyped it.  Example:

	$ git reabse
	WARNING: You called a Git program named 'reabse', which does
	not exist.
	Continuing under the assumption that you meant 'rebase'
	[...]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 10:14:58 -07:00
Junio C Hamano
7e44c93558 'git foo' program identifies itself without dash in die() messages
This is a mechanical conversion of all '*.c' files with:

	s/((?:die|error|warning)\("git)-(\S+:)/$1 $2/;

The result was manually inspected and no false positive was found.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 09:39:19 -07:00
Nguyễn Thái Ngọc Duy
bb528633b3 setup_git_directory(): fix move to worktree toplevel directory
When setup_git_directory() returns successfully, it is supposed to move
current working directory to worktree toplevel directory.

However, the code recomputing prefix inside setup_git_directory() has
to move cwd back to original working directory, in order to get new
prefix.  After that, it should move cwd back to worktree toplevel
directory as expected.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 23:41:12 -07:00
Nguyễn Thái Ngọc Duy
f83eafdd62 update-index: fix worktree setup
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 23:35:51 -07:00
Teemu Likonen
1707adb7f2 config.txt: Add missing colons after option name
gitcvs.usecrlfattr --> gitcvs.usecrlfattr::

This fixes an asciidoc markup issue.

Signed-off-by: Teemu Likonen <tlikonen@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 23:35:12 -07:00
Junio C Hamano
146ea068a0 git commit --author=$name: look $name up in existing commits
This allows "git commit --author=$name" to accept a name that is not in
the required "A U Thor <author@example.xz>" format, and use that to look
up an author name that matches from existing commits.

When using this feature, it is the user's responsibility to give a name
that uniquely matches the name s/he wants, as the logic returns the name
from the first matching commit.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 21:04:50 -07:00
Junio C Hamano
a5a818ee48 diff: vary default prefix depending on what are compared
With a new configuration "diff.mnemonicprefix", "git diff" shows the
differences between various combinations of preimage and postimage trees
with prefixes different from the standard "a/" and "b/".  Hopefully this
will make the distinction stand out for some people.

    "git diff" compares the (i)ndex and the (w)ork tree;
    "git diff HEAD" compares a (c)ommit and the (w)ork tree;
    "git diff --cached" compares a (c)ommit and the (i)ndex;
    "git-diff HEAD:file1 file2" compares an (o)bject and a (w)ork tree entity;
    "git diff --no-index a b" compares two non-git things (1) and (2).

Because these mnemonics now have meanings, they are swapped when reverse
diff is in effect and this feature is enabled.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 20:53:24 -07:00
Miklos Vajna
18668f5319 builtin-merge: avoid run_command_v_opt() for recursive and subtree
The try_merge_strategy() function always ran the strategy in a separate
process, though this is not always necessary. The recursive and subtree
strategy can be called without a fork(). This patch adds a check, and
calls recursive in the same process without wasting resources.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 20:47:11 -07:00
Miklos Vajna
8a2fce1895 merge-recursive: introduce merge_options
This makes it possible to avoid passing the labels of branches as
arguments to merge_recursive(), merge_trees() and
merge_recursive_generic().

It also takes care of subtree merge, output buffering, verbosity, and
rename limits - these were global variables till now in
merge-recursive.c.

A new function, named init_merge_options(), is introduced as well, it
clears the struct merge_info, then initializes with default values,
finally updates the default values based on the config and environment
variables.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 20:46:54 -07:00
Stephan Beyer
73118f89b8 merge-recursive.c: Add more generic merge_recursive_generic()
merge_recursive_generic() takes, in comparison to to merge_recursive(),
no commit ("struct commit *") arguments but SHA ids ("unsigned char *"),
and no commit list of bases but an array of refs ("const char **").

This makes it more generic in the case that it can also take the SHA
of a tree to merge trees without commits, for the bases, the head
and the remote.

merge_recursive_generic() also handles locking and updating of the
index, which is a common use case of merge_recursive().

This patch also rewrites builtin-merge-recursive.c to make use of
merge_recursive_generic().  By doing this, I stumbled over the
limitation of 20 bases and I've added a warning if this limitation
is exceeded.

This patch qualifies make_virtual_commit() as static again because
this function is not needed anymore outside merge-recursive.c.

Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 20:46:54 -07:00
Miklos Vajna
9047ebbc22 Split out merge_recursive() to merge-recursive.c
Move most of the of code from builtin-merge-recursive.c to a new file
merge-recursive.c and introduce merge_recursive_setup() in there so that
builtin-merge-recursive and other builtins call it.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 20:46:54 -07:00
Junio C Hamano
3928097020 diff: Help "less" hide ^M from the output
When the tracked contents have CRLF line endings, colored diff output
shows "^M" at the end of output lines, which is distracting, even though
the pager we use by default ("less") knows to hide them.

The problem is that "less" hides a carriage-return only at the end of the
line, immediately before a line feed.  The colored diff output does not
take this into account, and emits four element sequence for each line:

   - force this color;
   - the line up to but not including the terminating line feed;
   - reset color
   - line feed.

By including the carriage return at the end of the line in the second
item, we are breaking the smart our pager has in order not to show "^M".
This can be fixed by changing the sequence to:

   - force this color;
   - the line up to but not including the terminating end-of-line;
   - reset color
   - end-of-line.

where end-of-line is either a single linefeed or a CRLF pair.  When the
output is not colored, "force this color" and "reset color" sequences are
both empty, so we won't have this problem with or without this patch.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 20:34:45 -07:00
Junio C Hamano
7df437e56b Merge branch 'maint'
* maint:
  gitattributes: -crlf is not binary
  git-apply: Loosen "match_beginning" logic
  Fix example in git-name-rev documentation
  shell: do not play duplicated definition games to shrink the executable
  Fix use of hardlinks in "make install"
  pack-objects: Allow missing base objects when creating thin packs
2008-08-30 20:31:39 -07:00
Junio C Hamano
bbb896d8e1 gitattributes: -crlf is not binary
The description of crlf attribute incorrectly said that "-crlf" means
binary.  It is true that for binary files you would want "-crlf", but
that is not the same thing.

We also have supported attribute macros and via that mechanism a handy
"binary" to specify "-crlf -diff" at the same time.  It was not documented
anywhere as far as I can tell, even though the support was there from
the very beginning.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 20:30:45 -07:00
Junio C Hamano
0cf8581e33 checkout -m: recreate merge when checking out of unmerged index
This teaches git-checkout to recreate a merge out of unmerged
index entries while resolving conflicts.

With this patch, checking out an unmerged path from the index
now have the following possibilities:

 * Without any option, an attempt to checkout an unmerged path
   will atomically fail (i.e. no other cleanly-merged paths are
   checked out either);

 * With "-f", other cleanly-merged paths are checked out, and
   unmerged paths are ignored;

 * With "--ours" or "--theirs, the contents from the specified
   stage is checked out;

 * With "-m" (we should add "--merge" as synonym), the 3-way merge
   is recreated from the staged object names and checked out.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 19:57:55 -07:00
Junio C Hamano
29a1f99b4b Merge branch 'jc/maint-checkout-fix' into 'jc/better-conflict-resolution'
* jc/maint-checkout-fix:
  checkout --ours/--theirs: allow checking out one side of a conflicting merge
  checkout -f: allow ignoring unmerged paths when checking out of the index
  checkout: do not check out unmerged higher stages randomly
2008-08-30 19:44:26 -07:00
Junio C Hamano
c236bcd061 git-merge-recursive: learn to honor merge.conflictstyle
This teaches the low-level ll_xdl_merge() routine to honor
merge.conflictstyle configuration variable, so that merge-recursive
strategy can show the conflicts in the style of user's choice.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 19:41:44 -07:00
Junio C Hamano
b541248467 merge.conflictstyle: choose between "merge" and "diff3 -m" styles
This teaches "git merge-file" to honor merge.conflictstyle configuration
variable, whose value can be "merge" (default) or "diff3".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 19:41:44 -07:00
Junio C Hamano
387c9d4981 rerere: understand "diff3 -m" style conflicts with the original
This teaches rerere to grok conflicts expressed in "diff3 -m" style
output, where the version from the common ancestor is output after the
first side, preceded by a "|||||||" line.

The rerere database needs to keep only the versions from two sides, so the
code parses the original copy and discards it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 19:41:43 -07:00
Junio C Hamano
cc58d7dfdd rerere.c: use symbolic constants to keep track of parsing states
These hardcoded integers make the code harder to follow than necessary;
replace them with enums to make it easier to read, before adding support
for optionally parsing "diff3 -m" style conflict markers.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 19:41:43 -07:00
Junio C Hamano
83133740d9 xmerge.c: "diff3 -m" style clips merge reduction level to EAGER or less
When showing a conflicting merge result, and "--diff3 -m" style is asked
for, this patch makes sure that the merge reduction level does not exceed
XDL_MERGE_EAGER.  This is because "diff3 -m" style output would not make
sense for anything more aggressive than XDL_MERGE_EAGER, because of the
way how the merge reduction works.

"git merge-file" no longer has to force MERGE_EAGER when "--diff3" is
asked for because of this change.

Suppose a common ancestor (shared preimage) is modified to postimage #1
and #2 (each letter represents one line):

                     #####
    postimage#1: 1234ABCDE789
                    |    /
                    |   /
    preimage:    123456789
                    |   \
    postimage#2: 1234AXYE789
                     ####

XDL_MERGE_MINIMAL and XDL_MERGE_EAGER would:

 (1) find the s/56/ABCDE/ done on one side and s/56/AXYE/ done on the
     other side,

 (2) notice that they touch an overlapping area, and

 (3) mark it as a conflict, "ABCDE vs AXYE".

The difference between the two algorithms is that EAGER drops the hunk
altogether if the postimages match (i.e. both sides modified the same
way), while MINIMAL keeps it.  There is no other operation performed to
the hunk.  As the result, lines marked with "#" in the above picure will
be in the RCS merge style output like this (letters <, = and > represent
conflict marker lines):

    output:      1234<ABCDE=AXYE>789    ; with MINIMAL/EAGER

The part from the preimage that corresponds to these conflicting changes
is "56", which is what "diff3 -m" style output adds to it:

    output:      1234<ABCDE|56=AXYE>789 ; in "diff3 -m" style

Now, XDL_MERGE_ZEALOUS looks at the differences between the changes two
postimages made in order to reduce the number of lines in the conflicting
regions.  It notices that both sides start their new contents with "A",
and excludes it from the output (it also excludes "E" for the same
reason).  The conflict that used to be "ABCDE vs AXYE" is now "BCD vs XY":

    output:      1234A<BCD=XY>E789      ; with ZEALOUS

There could even be matching parts between two postimages in the middle.
Instead of one side rewriting the shared "56" to "ABCDE" and the other
side to "AXYE", imagine the case where the postimages are "ABCDE" and
"AXCYE", in which case instead of having one conflicted hunk "BCD vs XY",
you would have two conflicting hunks "B vs X" and "D vs Y".

In either case, once you reduce "ABCDE vs AXYE" to "BCD vs XY" (or "ABCDE
vs AXCYE" to "B vs X" and "D vs Y"), there is no part from the preimage
that corresponds to the conflicting change made in both postimages
anymore.  In other words, conflict reduced by ZEALOUS algorithm cannot be
expressed in "diff3 -m" style.  Representing the last illustration like
this is misleading to say the least:

    output:      1234A<BCD|56=XY>E789   ; broken "diff3 -m" style

because the preimage was not ...4A56E... to begin with.  "A" and "E" are
common only between the postimages.

Even worse, once a single conflicting hunk is split into multiple ones
(recall the example of breaking "ABCDE vs AXCYE" to "B vs X" and "D vs
Y"), there is no sane way to distribute the preimage text across split
conflicting hunks.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 19:41:43 -07:00
Junio C Hamano
838338cd22 xmerge.c: minimum readability fixups
This replaces hardcoded magic constants with symbolic ones for
readability, and swaps one if/else blocks to better match the
order in which 0/1/2 variables are handled to nearby codepath.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 19:41:43 -07:00