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17 commits

Author SHA1 Message Date
Junio C Hamano 06dbc1ea57 Merge branch 'jc/conflict-marker-size'
* jc/conflict-marker-size:
  rerere: honor conflict-marker-size attribute
  rerere: prepare for customizable conflict marker length
  conflict-marker-size: new attribute
  rerere: use ll_merge() instead of using xdl_merge()
  merge-tree: use ll_merge() not xdl_merge()
  xdl_merge(): allow passing down marker_size in xmparam_t
  xdl_merge(): introduce xmparam_t for merge specific parameters
  git_attr(): fix function signature

Conflicts:
	builtin-merge-file.c
	ll-merge.c
	xdiff/xdiff.h
	xdiff/xmerge.c
2010-01-20 20:28:51 -08:00
Junio C Hamano 00f8f97d30 xdl_merge(): introduce xmparam_t for merge specific parameters
So far we have only needed to be able to pass an option that is generic to
xdiff family of functions to this function.  Extend the interface so that
we can give it merge specific parameters.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-16 21:33:13 -08:00
Junio C Hamano 73eb40eeaa git-merge-file --ours, --theirs
Sometimes people want their conflicting merges autoresolved by
favouring upstream changes.  The standard answer they are given is
to run "git diff --name-only | xargs git checkout MERGE_HEAD --" in
such a case.  This is to accept automerge results for the paths that
are fully resolved automatically, while taking their version of the
file in full for paths that have conflicts.

This is problematic on two counts.

One is that this is not exactly what these people want.  It discards
all changes they did on their branch for any paths that conflicted.
They usually want to salvage as much automerge result as possible in
a conflicted file, and want to take the upstream change only in the
conflicted part.

This patch teaches two new modes of operation to the lowest-lever
merge machinery, xdl_merge().  Instead of leaving the conflicted
lines from both sides enclosed in <<<, ===, and >>> markers, the
conflicts are resolved favouring our side or their side of changes.

A larger problem is that this tends to encourage a bad workflow by
allowing people to record such a mixed up half-merged result as a
full commit without auditing.  This commit does not tackle this
issue at all.  In git, we usually give long enough rope to users
with strange wishes as long as the risky features are not enabled by
default, and this is such a risky feature.

Signed-off-by: Avery Pennarun <apenwarr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-11-29 23:11:46 -08:00
Stephen Boyd 3778292017 parse-opts: prepare for OPT_FILENAME
To give OPT_FILENAME the prefix, we pass the prefix to parse_options()
which passes the prefix to parse_options_start() which sets the prefix
member of parse_opts_ctx accordingly. If there isn't a prefix in the
calling context, passing NULL will suffice.

Signed-off-by: Stephen Boyd <bebarino@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-25 01:07:25 -07:00
René Scharfe 4deba8b779 merge-file: handle freopen() failure
Report the error if redirection of stderr to /dev/null failed.

This silences a compiler warning about ignoring the return value
of freopen() on Ubuntu 8.10.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-12-26 19:10:02 -08:00
Pierre Habouzit d249610792 parse-opt: migrate builtin-merge-file.
Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-02 18:46:02 -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 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 e0af48e496 xdiff-merge: optionally show conflicts in "diff3 -m" style
When showing conflicting merges, we traditionally followed RCS's merge
output format.  The output shows:

 <<<<<<<
 postimage from one side;
 =======
 postimage of the other side; and
 >>>>>>>

Some poeple find it easier to be able to understand what is going on when
they can view the common ancestor's version, which is used by "diff3 -m",
which shows:

 <<<<<<<
 postimage from one side;
 |||||||
 shared preimage;
 =======
 postimage of the other side; and
 >>>>>>>

This is an initial step to bring that as an optional feature to git.
Only "git merge-file" has been converted, with "--diff3" option.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-30 19:41:43 -07:00
Junio C Hamano 16007f3916 Merge branch 'maint'
* maint:
  merge-file: handle empty files gracefully
  merge-recursive: handle file mode changes
  Minor wording changes in the keyboard descriptions in git-add --interactive.
  git fetch: Take '-n' to mean '--no-tags'
  quiltimport: fix misquoting of parsed -p<num> parameter
  git-quiltimport: better parser to grok "enhanced" series files.
2008-03-14 00:16:42 -07:00
Johannes Schindelin 381b851c9b merge-file: handle empty files gracefully
Earlier, it would error out while trying to read and/or writing them.
Now, calling merge-file with empty files is neither interesting nor
useful, but it is a bug that needed fixing.

Noticed by Clemens Buchacher.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2008-03-13 23:43:56 -07:00
Johannes Schindelin ee95ec5d58 xdl_merge(): introduce XDL_MERGE_ZEALOUS_ALNUM
When a merge conflicts, there are often common lines that are not really
common, such as empty lines or lines containing a single curly bracket.

With XDL_MERGE_ZEALOUS_ALNUM, we use the following heuristics: when a
hunk does not contain any letters or digits, it is treated as conflicting.

In other words, a conflict which used to look like this:

	<<<<<<<
					a = 1;
	=======
					output();
	>>>>>>>
				}
			}
		}

	<<<<<<<
		output();
	=======
		b = 1;
	>>>>>>>

will look like this with ZEALOUS_ALNUM:

	<<<<<<<
					a = 1;
				}
			}
		}

		output();
	=======
					output();
				}
			}
		}

		b = 1;
	>>>>>>>

To demonstrate this, git-merge-file has been switched from
XDL_MERGE_ZEALOUS to XDL_MERGE_ZEALOUS_ALNUM.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-18 00:10:37 -08:00
Peter Hagervall baffc0e770 Make every builtin-*.c file #include "builtin.h"
Make every builtin-*.c file #include "builtin.h".

Also takes care of some declaration/definition mismatches.

Signed-off-by: Peter Hagervall <hager@cs.umu.se>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-14 22:44:09 -07:00
Johannes Schindelin 5771907a57 git-merge-file: refuse to merge binary files
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-04 23:10:29 -07:00
Johannes Schindelin 7cab5883ff move read_mmfile() into xdiff-interface
read_file() was a useful function if you want to work with the xdiff stuff,
so it was renamed and put into a more central place.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-21 23:10:14 -08:00
Johannes Schindelin fbe0b24ca5 merge-file: support -p and -q; fix compile warnings
Now merge-file also understands --stdout and --quiet options. While
at it, two compile warnings were fixed.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-06 10:04:00 -08:00
Johannes Schindelin ba1f5f3537 Add builtin merge-file, a minimal replacement for RCS merge
merge-file has the same syntax as RCS merge, but supports only the
"-L" option.

For good measure, a test is added, which is quite minimal, though.

[jc: further fix for compliation errors included.]

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-06 10:00:24 -08:00