diff options
| -rw-r--r-- | Documentation/git-merge-tree.txt | 98 | ||||
| -rw-r--r-- | builtin/merge-tree.c | 41 | ||||
| -rwxr-xr-x | t/t4301-merge-tree-write-tree.sh | 106 |
3 files changed, 232 insertions, 13 deletions
diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt index 58731c1942..2a9c91328d 100644 --- a/Documentation/git-merge-tree.txt +++ b/Documentation/git-merge-tree.txt @@ -3,26 +3,100 @@ git-merge-tree(1) NAME ---- -git-merge-tree - Show three-way merge without touching index +git-merge-tree - Perform merge without touching index or working tree SYNOPSIS -------- [verse] -'git merge-tree' <base-tree> <branch1> <branch2> +'git merge-tree' [--write-tree] <branch1> <branch2> +'git merge-tree' [--trivial-merge] <base-tree> <branch1> <branch2> (deprecated) +[[NEWMERGE]] DESCRIPTION ----------- -Reads three tree-ish, and output trivial merge results and -conflicting stages to the standard output. This is similar to -what three-way 'git read-tree -m' does, but instead of storing the -results in the index, the command outputs the entries to the -standard output. - -This is meant to be used by higher level scripts to compute -merge results outside of the index, and stuff the results back into the -index. For this reason, the output from the command omits -entries that match the <branch1> tree. + +This command has a modern `--write-tree` mode and a deprecated +`--trivial-merge` mode. With the exception of the +<<DEPMERGE,DEPRECATED DESCRIPTION>> section at the end, the rest of +this documentation describes modern `--write-tree` mode. + +Performs a merge, but does not make any new commits and does not read +from or write to either the working tree or index. + +The performed merge will use the same feature as the "real" +linkgit:git-merge[1], including: + + * three way content merges of individual files + * rename detection + * proper directory/file conflict handling + * recursive ancestor consolidation (i.e. when there is more than one + merge base, creating a virtual merge base by merging the merge bases) + * etc. + +After the merge completes, a new toplevel tree object is created. See +`OUTPUT` below for details. + +[[OUTPUT]] +OUTPUT +------ + +For either a successful or conflicted merge, the output from +git-merge-tree is simply one line: + + <OID of toplevel tree> + +The printed tree object corresponds to what would be checked out in +the working tree at the end of `git merge`, and thus may have files +with conflict markers in them. + +EXIT STATUS +----------- + +For a successful, non-conflicted merge, the exit status is 0. When the +merge has conflicts, the exit status is 1. If the merge is not able to +complete (or start) due to some kind of error, the exit status is +something other than 0 or 1 (and the output is unspecified). + +USAGE NOTES +----------- + +This command is intended as low-level plumbing, similar to +linkgit:git-hash-object[1], linkgit:git-mktree[1], +linkgit:git-commit-tree[1], linkgit:git-write-tree[1], +linkgit:git-update-ref[1], and linkgit:git-mktag[1]. Thus, it can be +used as a part of a series of steps such as: + + NEWTREE=$(git merge-tree --write-tree $BRANCH1 $BRANCH2) + test $? -eq 0 || die "There were conflicts..." + NEWCOMMIT=$(git commit-tree $NEWTREE -p $BRANCH1 -p $BRANCH2) + git update-ref $BRANCH1 $NEWCOMMIT + +[[DEPMERGE]] +DEPRECATED DESCRIPTION +---------------------- + +Per the <<NEWMERGE,DESCRIPTION>> and unlike the rest of this +documentation, this section describes the deprecated `--trivial-merge` +mode. + +Other than the optional `--trivial-merge`, this mode accepts no +options. + +This mode reads three tree-ish, and outputs trivial merge results and +conflicting stages to the standard output in a semi-diff format. +Since this was designed for higher level scripts to consume and merge +the results back into the index, it omits entries that match +<branch1>. The result of this second form is similar to what +three-way 'git read-tree -m' does, but instead of storing the results +in the index, the command outputs the entries to the standard output. + +This form not only has limited applicability (a trivial merge cannot +handle content merges of individual files, rename detection, proper +directory/file conflict handling, etc.), the output format is also +difficult to work with, and it will generally be less performant than +the first form even on successful merges (especially if working in +large repositories). GIT --- diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c index 0f9d928e86..2332525d8b 100644 --- a/builtin/merge-tree.c +++ b/builtin/merge-tree.c @@ -2,6 +2,9 @@ #include "builtin.h" #include "tree-walk.h" #include "xdiff-interface.h" +#include "help.h" +#include "commit-reach.h" +#include "merge-ort.h" #include "object-store.h" #include "parse-options.h" #include "repository.h" @@ -398,7 +401,43 @@ struct merge_tree_options { static int real_merge(struct merge_tree_options *o, const char *branch1, const char *branch2) { - die(_("real merges are not yet implemented")); + struct commit *parent1, *parent2; + struct commit_list *merge_bases = NULL; + struct merge_options opt; + struct merge_result result = { 0 }; + + parent1 = get_merge_parent(branch1); + if (!parent1) + help_unknown_ref(branch1, "merge-tree", + _("not something we can merge")); + + parent2 = get_merge_parent(branch2); + if (!parent2) + help_unknown_ref(branch2, "merge-tree", + _("not something we can merge")); + + init_merge_options(&opt, the_repository); + + opt.show_rename_progress = 0; + + opt.branch1 = branch1; + opt.branch2 = branch2; + + /* + * Get the merge bases, in reverse order; see comment above + * merge_incore_recursive in merge-ort.h + */ + merge_bases = get_merge_bases(parent1, parent2); + if (!merge_bases) + die(_("refusing to merge unrelated histories")); + merge_bases = reverse_commit_list(merge_bases); + + merge_incore_recursive(&opt, merge_bases, parent1, parent2, &result); + if (result.clean < 0) + die(_("failure to merge")); + puts(oid_to_hex(&result.tree->object.oid)); + merge_finalize(&opt, &result); + return !result.clean; /* result.clean < 0 handled above */ } int cmd_merge_tree(int argc, const char **argv, const char *prefix) diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh new file mode 100755 index 0000000000..6d321652e2 --- /dev/null +++ b/t/t4301-merge-tree-write-tree.sh @@ -0,0 +1,106 @@ +#!/bin/sh + +test_description='git merge-tree --write-tree' + +. ./test-lib.sh + +# This test is ort-specific +if test "$GIT_TEST_MERGE_ALGORITHM" != "ort" +then + skip_all="GIT_TEST_MERGE_ALGORITHM != ort" + test_done +fi + +test_expect_success setup ' + test_write_lines 1 2 3 4 5 >numbers && + echo hello >greeting && + echo foo >whatever && + git add numbers greeting whatever && + test_tick && + git commit -m initial && + + git branch side1 && + git branch side2 && + git branch side3 && + + git checkout side1 && + test_write_lines 1 2 3 4 5 6 >numbers && + echo hi >greeting && + echo bar >whatever && + git add numbers greeting whatever && + test_tick && + git commit -m modify-stuff && + + git checkout side2 && + test_write_lines 0 1 2 3 4 5 >numbers && + echo yo >greeting && + git rm whatever && + mkdir whatever && + >whatever/empty && + git add numbers greeting whatever/empty && + test_tick && + git commit -m other-modifications && + + git checkout side3 && + git mv numbers sequence && + test_tick && + git commit -m rename-numbers +' + +test_expect_success 'Clean merge' ' + TREE_OID=$(git merge-tree --write-tree side1 side3) && + q_to_tab <<-EOF >expect && + 100644 blob $(git rev-parse side1:greeting)Qgreeting + 100644 blob $(git rev-parse side1:numbers)Qsequence + 100644 blob $(git rev-parse side1:whatever)Qwhatever + EOF + + git ls-tree $TREE_OID >actual && + test_cmp expect actual +' + +test_expect_success 'Content merge and a few conflicts' ' + git checkout side1^0 && + test_must_fail git merge side2 && + expected_tree=$(git rev-parse AUTO_MERGE) && + + # We will redo the merge, while we are still in a conflicted state! + test_when_finished "git reset --hard" && + + test_expect_code 1 git merge-tree --write-tree side1 side2 >RESULT && + actual_tree=$(head -n 1 RESULT) && + + # Due to differences of e.g. "HEAD" vs "side1", the results will not + # exactly match. Dig into individual files. + + # Numbers should have three-way merged cleanly + test_write_lines 0 1 2 3 4 5 6 >expect && + git show ${actual_tree}:numbers >actual && + test_cmp expect actual && + + # whatever and whatever~<branch> should have same HASHES + git rev-parse ${expected_tree}:whatever ${expected_tree}:whatever~HEAD >expect && + git rev-parse ${actual_tree}:whatever ${actual_tree}:whatever~side1 >actual && + test_cmp expect actual && + + # greeting should have a merge conflict + git show ${expected_tree}:greeting >tmp && + sed -e s/HEAD/side1/ tmp >expect && + git show ${actual_tree}:greeting >actual && + test_cmp expect actual +' + +test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' ' + # Mis-spell with single "s" instead of double "s" + test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect && + + grep "error: unknown option.*mesages" expect +' + +test_expect_success 'Barf on too many arguments' ' + test_expect_code 129 git merge-tree --write-tree side1 side2 invalid 2>expect && + + grep "^usage: git merge-tree" expect +' + +test_done |