kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
Jonathan Nieder	349362cc20	xdiff: cast arguments for ctype functions to unsigned char The ctype functions isspace(), isalnum(), et al take an integer argument representing an unsigned character, or -1 for EOF. On platforms with a signed char, it is unsafe to pass a char to them without casting it to unsigned char first. Most of git is already shielded against this by the ctype implementation in git-compat-util.h, but xdiff, which uses libc ctype.h, ought to be fixed. Noticed-by: der Mouse <mouse@Rodents-Montreal.ORG> Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	14 years ago
Alexey Mahotkin	c8c073c420	xdiff/xmerge.c: use memset() instead of explicit for-loop memset() is heavily optimized, and resulting assembler code is about 150 lines less for that file. Signed-off-by: Alexey Mahotkin <squadette@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
Jonathan Nieder	a4b5e91c49	xdl_merge(): move file1 and file2 labels to xmparam structure The labels for the three participants in a potential conflict are all optional arguments for the xdiff merge routine; if they are NULL, then xdl_merge() can cope by omitting the labels from its output. Move them to the xmparam structure to allow new callers to save some keystrokes where they are not needed. This also has the virtue of making the xdiff merge interface more similar to merge_trees, which might make it easier to learn. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
Jonathan Nieder	8a161433a0	xdl_merge(): add optional ancestor label to diff3-style output The ‘git checkout --conflict=diff3’ command can be used to present conflicts hunks including text from the common ancestor: <<<<<<< ours ourside \|\|\|\|\|\|\| original ======= theirside >>>>>>> theirs The added information is helpful for resolving merges by hand, and merge tools can usually grok it because it is very similar to the output from diff3 -m. A subtle change can help more tools to understand the output. ‘diff3’ includes the name of the merge base on the \|\|\|\|\|\|\| line of the output, and some tools misparse the conflict hunks without it. Add a new xmp->ancestor parameter to xdl_merge() for use with conflict style XDL_MERGE_DIFF3 as a label on the \|\|\|\|\|\|\| line for any conflict hunks. If xmp->ancestor is NULL, the output format is unchanged. Thus, this change only provides unexposed plumbing for the new feature; it does not affect the outward behavior of git. Requested-by: Stefan Monnier <monnier@iro.umontreal.ca> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Acked-by: Bert Wesarg <Bert.Wesarg@googlemail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
Bert Wesarg	560119b9ab	refactor merge flags into xmparam_t Include the merge level, favor, and style flags into the xmparam_t struct. This removes the bit twiddling with these three values into the one flags parameter. Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
Bert Wesarg	cd1d61c44f	make union merge an xdl merge favor The current union merge driver is implemented as an post process. But the xdl_merge code is quite capable to produce the result by itself. Therefore move it there. Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
Junio C Hamano	9914cf4689	xdl_merge(): allow passing down marker_size in xmparam_t This allows the callers of xdl_merge() to pass marker_size (defaults to 7) in xmparam_t argument, to use conflict markers of non-default length. Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
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>	15 years ago
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>	15 years ago
Charles Bailey	5719db91ce	Change xdl_merge to generate output even for null merges xdl_merge used to have a check to ensure that there was at least some change in one or other side being merged but this suppressed output for the degenerate case when base, local and remote contents were all identical. Removing this check enables correct output in the degenerate case and xdl_free_script handles freeing NULL scripts so there is no need to have the check for these calls. Signed-off-by: Charles Bailey <charles@hashpling.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago
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>	16 years ago
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>	16 years ago
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>	16 years ago
Junio C Hamano	f2b25dd81f	xdl_fill_merge_buffer(): separate out a too deeply nested function This simply moves code around to make a separate function that prepares a single conflicted hunk with markers into the buffer. Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago
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>	17 years ago
Johannes Schindelin	f407f14dea	xdl_merge(): make XDL_MERGE_ZEALOUS output simpler When a merge conflicts, there are often less than three common lines between two conflicting regions. Since a conflict takes up as many lines as are conflicting, plus three lines for the commit markers, the output will be shorter (and thus, simpler) in this case, if the common lines will be merged into the conflicting regions. This patch merges up to three common lines into the conflicts. For example, what looked like this before this patch: <<<<<<< if (a == 1) ======= if (a != 0) >>>>>>> { int i; <<<<<<< a = 0; ======= a = !a; >>>>>>> will now look like this: <<<<<<< if (a == 1) { int i; a = 0; ======= if (a != 0) { int i; a = !a; >>>>>>> Suggested Linus (based on ideas by "Voltage Spike" -- if that name is real, it is mighty cool). Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	17 years ago
Johannes Schindelin	22b6abcd08	Fix yet another subtle xdl_merge() bug In very obscure cases, a merge can hit an unexpected code path (where the original code went as far as saying that this was a bug). This failing merge was noticed by Alexandre Juillard. The problem is that the original file contains something like this: -- snip -- two non-empty lines before two empty lines after two empty lines -- snap -- and this snippet is reduced to _one_ empty line in _both_ new files. However, it is ambiguous as to which hunk takes the empty line: the first or the second one? Indeed in Alexandre's example files, the xdiff algorithm attributes the empty line to the first hunk in one case, and to the second hunk in the other case. (Trimming down the example files _changes_ that behaviour!) Thus, the call to xdl_merge_cmp_lines() has no chance to realize that the change is actually identical in both new files. Therefore, xdl_refine_conflicts() finds an empty diff script, which was not expected there, because (the original author of xdl_merge() thought) xdl_merge_cmp_lines() would catch that case earlier. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Johannes Schindelin	5d6b151fdd	xdl_merge(): fix a segmentation fault when refining conflicts The function xdl_refine_conflicts() tries to break down huge conflicts by doing a diff on the conflicting regions. However, this does not make sense when one side is empty. Worse, when one side is not only empty, but after EOF, the code accessed unmapped memory. Noticed by Luben Tuikov, Shawn Pearce and Alexandre Julliard, the latter providing a test case. Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Johannes Schindelin	98e6da8a36	xdl_merge(): fix and simplify conflict handling Suppose you have changes in new1 to the original lines 10-20, and changes in new2 to the original lines 15-25, then the changes to 10-25 conflict. But it is possible that the next changes in new1 still overlap with this change to new2. So, in the next iteration we have to look at the same change to new2 again. The old code tried to be a bit too clever. The new code is shorter and more to the point: do not fiddle with the ranges at all. Also, xdl_append_merge() tries harder to combine conflicts. This is necessary, because with the above simplification, some conflicts would not be recognized as conflicts otherwise: In the above scenario, it is possible that there is no other change to new1. Absent the combine logic, the change in new2 would be recorded _again_, but as a non-conflict. Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>	18 years ago
Johannes Schindelin	710daa83fc	xdl_merge(): fix thinko If one side's block (of changed lines) ends later than the other side's block, the former should be tested against the next block of the other side, not vice versa. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Johannes Schindelin	875b8ce476	xdl_merge(): fix an off-by-one bug The line range is i1 .. (i1 + chg1 - 1), not i1 .. (i1 + chg1). Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Junio C Hamano	53a7085a10	xmerge: make return value from xdl_merge() more usable. The callers would want to know if the resulting merge is clean; do not discard that information away after calling xdl_do_merge(). Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Johannes Schindelin	857b933e04	xdiff: add xdl_merge() This new function implements the functionality of RCS merge, but in-memory. It returns < 0 on error, otherwise the number of conflicts. Finding the conflicting lines can be a very expensive task. You can control the eagerness of this algorithm: - a level value of 0 means that all overlapping changes are treated as conflicts, - a value of 1 means that if the overlapping changes are identical, it is not treated as a conflict. - If you set level to 2, overlapping changes will be analyzed, so that almost identical changes will not result in huge conflicts. Rather, only the conflicting lines will be shown inside conflict markers. With each increasing level, the algorithm gets slower, but more accurate. Note that the code for level 2 depends on the simple definition of mmfile_t specific to git, and therefore it will be harder to port that to LibXDiff. Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago

25 Commits (675a0fe297e88e0fab2ee9b311d4ebb3c3bfef28)