path: root/builtin/merge-recursive.c
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2019-08-19Ensure index matches head before invoking merge machinery, round NElijah Newren
This is the bug that just won't die; there always seems to be another form of it somewhere. See the commit message of 55f39cf7551b ("merge: fix misleading pre-merge check documentation", 2018-06-30) for a more detailed explanation), but in short: <quick summary> builtin/merge.c contains this important requirement for merge strategies: ...the index must be in sync with the head commit. The strategies are responsible to ensure this. This condition is important to enforce because there are two likely failure cases when the index isn't in sync with the head commit: * we silently throw away changes the user had staged before the merge * we accidentally (and silently) include changes in the merge that were not part of either of the branches/trees being merged Discarding users' work and mis-merging are both bad outcomes, especially when done silently, so naturally this rule was stated sternly -- but, unfortunately totally ignored in practice unless and until actual bugs were found. But, fear not: the bugs from this were fixed in commit ee6566e8d70d ("[PATCH] Rewrite read-tree", 2005-09-05) through a rewrite of read-tree (again, commit 55f39cf7551b has a more detailed explanation of how this affected merge). And it was fixed again in commit 160252f81626 ("git-merge-ours: make sure our index matches HEAD", 2005-11-03) ...and it was fixed again in commit 3ec62ad9ffba ("merge-octopus: abort if index does not match HEAD", 2016-04-09) ...and again in commit 65170c07d466 ("merge-recursive: avoid incorporating uncommitted changes in a merge", 2017-12-21) ...and again in commit eddd1a411d93 ("merge-recursive: enforce rule that index matches head before merging", 2018-06-30) ...with multiple testcases added to the testsuite that could be enumerated in even more commits. Then, finally, in a patch in the same series as the last fix above, the documentation about this requirement was fixed in commit 55f39cf7551b ("merge: fix misleading pre-merge check documentation", 2018-06-30), and we all lived happily ever after... </quick summary> Unfortunately, "ever after" apparently denotes a limited time and it expired today. The merge-recursive rule to enforce that index matches head was at the beginning of merge_trees() and would only trigger when opt->call_depth was 0. Since merge_recursive() doesn't call merge_trees() until after returning from recursing, this meant that the check wasn't triggered by merge_recursive() until it had first finished all the intermediate merges to create virtual merge bases. That is a potentially HUGE amount of computation (and writing of intermediate merge results into the .git/objects directory) before it errors out and says, in effect, "Sorry, I can't do any merging because you have some local changes that would be overwritten." Trying to enforce that all of merge_trees(), merge_recursive(), and merge_recursive_generic() checked the index == head condition earlier resulted in a bunch of broken tests. It turns out that merge_recursive() has code to drop and reload the cache while recursing to create intermediate virtual merge bases, but unfortunately that code runs even when no recursion is necessary. This unconditional dropping and reloading of the cache masked a few bugs: * builtin/merge-recursive.c: didn't even bother loading the index. * builtin/stash.c: feels like a fake 'builtin' because it repeatedly invokes git subprocesses all over the place, mixed with other operations. In particular, invoking "git reset" will reset the index on disk, but the parent process that invoked it won't automatically have its in-memory index updated. * t3030-merge-recursive.h: this test has always been broken in that it didn't make sure to make index match head before running. But, it didn't care about the index or even the merge result, just the verbose output while running. While commit eddd1a411d93 ("merge-recursive: enforce rule that index matches head before merging", 2018-06-30) should have uncovered this broken test, it used a test_must_fail wrapper around the merge-recursive call because it was known that the merge resulted in a rename/rename conflict. Thus, that fix only made this test fail for a different reason, and since the index == head check didn't happen until after coming all the way back out of the recursion, the testcase had enough information to pass the one check that it did perform. So, load the index in builtin/merge-recursive.c, reload the in-memory index in builtin/stash.c, and modify the t3030 testcase to correctly setup the index and make sure that the test fails in the expected way (meaning it reports a rename/rename conflict). This makes sure that all callers actually make the index match head. The next commit will then enforce the condition that index matches head earlier so this problem doesn't return in the future. Signed-off-by: Elijah Newren <> Signed-off-by: Junio C Hamano <>
2019-02-07Merge branch 'nd/the-index-final'Junio C Hamano
The assumption to work on the single "in-core index" instance has been reduced from the library-ish part of the codebase. * nd/the-index-final: cache.h: flip NO_THE_INDEX_COMPATIBILITY_MACROS switch read-cache.c: remove the_* from index_has_changes() merge-recursive.c: remove implicit dependency on the_repository merge-recursive.c: remove implicit dependency on the_index sha1-name.c: remove implicit dependency on the_index read-cache.c: replace update_index_if_able with repo_& read-cache.c: kill read_index() checkout: avoid the_index when possible repository.c: replace hold_locked_index() with repo_hold_locked_index() notes-utils.c: remove the_repository references grep: use grep_opt->repo instead of explict repo argument
2019-01-14merge-recursive.c: remove implicit dependency on the_indexNguyễn Thái Ngọc Duy
Signed-off-by: Nguyễn Thái Ngọc Duy <> Signed-off-by: Junio C Hamano <>
2019-01-12merge-recursive: copy $GITHEAD stringsJeff King
If $GITHEAD_1234abcd is set in the environment, we use its value as a "better branch name" in generating conflict markers. However, we pick these better names early in the process, and the return value from getenv() is not guaranteed to stay valid. Let's make a copy of the returned string. And to make memory management easier, let's just always return an allocated string from better_branch_name(), so we know that it must always be freed. Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
2018-07-16builtin/merge-recursive: make hash independentbrian m. carlson
Use GIT_MAX_HEXSZ instead of GIT_SHA1_HEXSZ for an allocation so that it is sufficiently large. Switch a comparison to use the_hash_algo to determine the length of a hex object ID. Signed-off-by: brian m. carlson <> Signed-off-by: Junio C Hamano <>
2016-09-15i18n: merge-recursive: mark verbose message for translationVasco Almeida
Signed-off-by: Vasco Almeida <> Signed-off-by: Junio C Hamano <>
2016-09-15i18n: merge-recursive: mark error messages for translationVasco Almeida
Spell the first word of such error messages in lowercase, following the usual style. Signed-off-by: Vasco Almeida <> Signed-off-by: Junio C Hamano <>
2016-06-28merge-recursive: convert merge_recursive_generic() to object_idbrian m. carlson
Convert this function and the git merge-recursive subcommand to use struct object_id. Signed-off-by: brian m. carlson <> Signed-off-by: Junio C Hamano <>
2015-09-25convert trivial sprintf / strcpy calls to xsnprintfJeff King
We sometimes sprintf into fixed-size buffers when we know that the buffer is large enough to fit the input (either because it's a constant, or because it's numeric input that is bounded in size). Likewise with strcpy of constant strings. However, these sites make it hard to audit sprintf and strcpy calls for buffer overflows, as a reader has to cross-reference the size of the array with the input. Let's use xsnprintf instead, which communicates to a reader that we don't expect this to overflow (and catches the mistake in case we do). Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
2013-12-05replace {pre,suf}fixcmp() with {starts,ends}_with()Christian Couder
Leaving only the function definitions and declarations so that any new topic in flight can still make use of the old functions, replace existing uses of the prefixcmp() and suffixcmp() with new API functions. The change can be recreated by mechanically applying this: $ git grep -l -e prefixcmp -e suffixcmp -- \*.c | grep -v strbuf\\.c | xargs perl -pi -e ' s|!prefixcmp\(|starts_with\(|g; s|prefixcmp\(|!starts_with\(|g; s|!suffixcmp\(|ends_with\(|g; s|suffixcmp\(|!ends_with\(|g; ' on the result of preparatory changes in this series. Signed-off-by: Christian Couder <> Signed-off-by: Junio C Hamano <>
2011-03-22Fix sparse warningsStephen Boyd
Fix warnings from 'make check'. - These files don't include 'builtin.h' causing sparse to complain that cmd_* isn't declared: builtin/clone.c:364, builtin/fetch-pack.c:797, builtin/fmt-merge-msg.c:34, builtin/hash-object.c:78, builtin/merge-index.c:69, builtin/merge-recursive.c:22 builtin/merge-tree.c:341, builtin/mktag.c:156, builtin/notes.c:426 builtin/notes.c:822, builtin/pack-redundant.c:596, builtin/pack-refs.c:10, builtin/patch-id.c:60, builtin/patch-id.c:149, builtin/remote.c:1512, builtin/remote-ext.c:240, builtin/remote-fd.c:53, builtin/reset.c:236, builtin/send-pack.c:384, builtin/unpack-file.c:25, builtin/var.c:75 - These files have symbols which should be marked static since they're only file scope: submodule.c:12, diff.c:631, replace_object.c:92, submodule.c:13, submodule.c:14, trace.c:78, transport.c:195, transport-helper.c:79, unpack-trees.c:19, url.c:3, url.c:18, url.c:104, url.c:117, url.c:123, url.c:129, url.c:136, thread-utils.c:21, thread-utils.c:48 - These files redeclare symbols to be different types: builtin/index-pack.c:210, parse-options.c:564, parse-options.c:571, usage.c:49, usage.c:58, usage.c:63, usage.c:72 - These files use a literal integer 0 when they really should use a NULL pointer: daemon.c:663, fast-import.c:2942, imap-send.c:1072, notes-merge.c:362 While we're in the area, clean up some unused #includes in builtin files (mostly exec_cmd.h). Signed-off-by: Stephen Boyd <> Signed-off-by: Junio C Hamano <>
2010-10-27Merge branch 'jf/merge-ignore-ws'Junio C Hamano
* jf/merge-ignore-ws: merge-recursive: options to ignore whitespace changes merge-recursive --patience ll-merge: replace flag argument with options struct merge-recursive: expose merge options for builtin merge
2010-09-03Merge branch 'jn/merge-renormalize'Junio C Hamano
* jn/merge-renormalize: merge-recursive --renormalize rerere: never renormalize rerere: migrate to parse-options API t4200 (rerere): modernize style ll-merge: let caller decide whether to renormalize ll-merge: make flag easier to populate Documentation/technical: document ll_merge merge-trees: let caller decide whether to renormalize merge-trees: push choice to renormalize away from low level t6038 (merge.renormalize): check that it can be turned off t6038 (merge.renormalize): try checkout -m and cherry-pick t6038 (merge.renormalize): style nitpicks Don't expand CRLFs when normalizing text during merge Try normalizing files to avoid delete/modify conflicts when merging Avoid conflicts when merging branches with mixed normalization Conflicts: builtin/rerere.c t/
2010-09-03builtin/merge_recursive.c: Add an usage string and make use of it.Thiago Farina
This improves the usage output by adding builtin_merge_recursive_usage string that follows the same pattern used by the other builtin commands. The previous output for git merger-recursive was: usage: merge-recursive <base>... -- <head> <remote> ... Now the output is: usage: git merge-recursive <base>... -- <head> <remote> ... Since cmd_merge_recursive is used to handle four different commands we need the %s in the usage string, so the following example: $ git merge-subtree -h Will output: usage: git merge-subtree <base>... -- <head> <remote> ... Signed-off-by: Thiago Farina <> Signed-off-by: Junio C Hamano <>
2010-08-26merge-recursive --patienceJustin Frankel
Teach the merge-recursive strategy a --patience option to use the "patience diff" algorithm, which tends to improve results when cherry-picking a patch that reorders functions at the same time as refactoring them. To support this, struct merge_options and ll_merge_options gain an xdl_opts member, so programs can use arbitrary xdiff flags (think "XDF_IGNORE_WHITESPACE") in a git-aware merge. git merge and git rebase can be passed the -Xpatience option to use this. [jn: split from --ignore-space patch; with documentation] Signed-off-by: Justin Frankel <> Signed-off-by: Jonathan Nieder <> Signed-off-by: Junio C Hamano <>
2010-08-26merge-recursive: expose merge options for builtin mergeJonathan Nieder
There are two very similar blocks of code that recognize options for the "recursive" merge strategy. Unify them. No functional change intended. Cc: Avery Pennarun <> Helped-by: Junio C Hamano <> Signed-off-by: Jonathan Nieder <> Signed-off-by: Junio C Hamano <>
2010-08-06merge-recursive --renormalizeJonathan Nieder
Teach "git merge-recursive" a --renormalize option to enable the merge.renormalize configuration. The --no-renormalize option can be used to override it in the negative. So in the future, you might be able to, e.g.: git checkout -m -Xrenormalize otherbranch or git revert -Xrenormalize otherpatch or git pull --rebase -Xrenormalize The bad part: merge.renormalize is still not honored for most commands. And it reveals lots of places that -X has not been plumbed in (so we get "git merge -Xrenormalize" but not much else). NEEDSWORK: tests Cc: Eyvind Bernhardsen <> Signed-off-by: Jonathan Nieder <> Signed-off-by: Junio C Hamano <>
2010-02-22Move 'builtin-*' into a 'builtin/' subdirectoryLinus Torvalds
This shrinks the top-level directory a bit, and makes it much more pleasant to use auto-completion on the thing. Instead of [torvalds@nehalem git]$ em buil<tab> Display all 180 possibilities? (y or n) [torvalds@nehalem git]$ em builtin-sh builtin-shortlog.c builtin-show-branch.c builtin-show-ref.c builtin-shortlog.o builtin-show-branch.o builtin-show-ref.o [torvalds@nehalem git]$ em builtin-shor<tab> builtin-shortlog.c builtin-shortlog.o [torvalds@nehalem git]$ em builtin-shortlog.c you get [torvalds@nehalem git]$ em buil<tab> [type] builtin/ builtin.h [torvalds@nehalem git]$ em builtin [auto-completes to] [torvalds@nehalem git]$ em builtin/sh<tab> [type] shortlog.c shortlog.o show-branch.c show-branch.o show-ref.c show-ref.o [torvalds@nehalem git]$ em builtin/sho [auto-completes to] [torvalds@nehalem git]$ em builtin/shor<tab> [type] shortlog.c shortlog.o [torvalds@nehalem git]$ em builtin/shortlog.c which doesn't seem all that different, but not having that annoying break in "Display all 180 possibilities?" is quite a relief. NOTE! If you do this in a clean tree (no object files etc), or using an editor that has auto-completion rules that ignores '*.o' files, you won't see that annoying 'Display all 180 possibilities?' message - it will just show the choices instead. I think bash has some cut-off around 100 choices or something. So the reason I see this is that I'm using an odd editory, and thus don't have the rules to cut down on auto-completion. But you can simulate that by using 'ls' instead, or something similar. Signed-off-by: Linus Torvalds <> Signed-off-by: Junio C Hamano <>