From 66265a693e8deb3ab86577eb7f69940410044081 Mon Sep 17 00:00:00 2001 From: Kyle Zhao Date: Fri, 11 Nov 2022 23:45:13 +0000 Subject: [PATCH 1/3] merge-tree.c: add --merge-base= option This patch will give our callers more flexibility to use `git merge-tree`, such as: git merge-tree --write-tree --merge-base=branch^ HEAD branch This does a merge of HEAD and branch, but uses branch^ as the merge-base. And the reason why using an option flag instead of a positional argument is to allow additional commits passed to merge-tree to be handled via an octopus merge in the future. Signed-off-by: Kyle Zhao Signed-off-by: Taylor Blau --- Documentation/git-merge-tree.txt | 4 +++ builtin/merge-tree.c | 46 ++++++++++++++++++++++++-------- t/t4301-merge-tree-write-tree.sh | 27 +++++++++++++++++++ 3 files changed, 66 insertions(+), 11 deletions(-) diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt index 04bcc416e6..d9dacb2ce5 100644 --- a/Documentation/git-merge-tree.txt +++ b/Documentation/git-merge-tree.txt @@ -64,6 +64,10 @@ OPTIONS share no common history. This flag can be given to override that check and make the merge proceed anyway. +--merge-base=:: + Instead of finding the merge-bases for and , + specify a merge-base for the merge. + [[OUTPUT]] OUTPUT ------ diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c index fe853aa8f9..62c6d43cdb 100644 --- a/builtin/merge-tree.c +++ b/builtin/merge-tree.c @@ -3,6 +3,7 @@ #include "tree-walk.h" #include "xdiff-interface.h" #include "help.h" +#include "commit.h" #include "commit-reach.h" #include "merge-ort.h" #include "object-store.h" @@ -406,6 +407,7 @@ struct merge_tree_options { }; static int real_merge(struct merge_tree_options *o, + const char *merge_base, const char *branch1, const char *branch2, const char *prefix) { @@ -432,16 +434,31 @@ static int real_merge(struct merge_tree_options *o, 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 && !o->allow_unrelated_histories) - die(_("refusing to merge unrelated histories")); - merge_bases = reverse_commit_list(merge_bases); + if (merge_base) { + struct commit *base_commit; + struct tree *base_tree, *parent1_tree, *parent2_tree; + + base_commit = lookup_commit_reference_by_name(merge_base); + if (!base_commit) + die(_("could not lookup commit %s"), merge_base); + + opt.ancestor = merge_base; + base_tree = get_commit_tree(base_commit); + parent1_tree = get_commit_tree(parent1); + parent2_tree = get_commit_tree(parent2); + merge_incore_nonrecursive(&opt, base_tree, parent1_tree, parent2_tree, &result); + } else { + /* + * 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 && !o->allow_unrelated_histories) + die(_("refusing to merge unrelated histories")); + merge_bases = reverse_commit_list(merge_bases); + merge_incore_recursive(&opt, merge_bases, parent1, parent2, &result); + } - merge_incore_recursive(&opt, merge_bases, parent1, parent2, &result); if (result.clean < 0) die(_("failure to merge")); @@ -487,6 +504,7 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) struct merge_tree_options o = { .show_messages = -1 }; int expected_remaining_argc; int original_argc; + const char *merge_base = NULL; const char * const merge_tree_usage[] = { N_("git merge-tree [--write-tree] [] "), @@ -515,6 +533,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) &o.use_stdin, N_("perform multiple merges, one per line of input"), PARSE_OPT_NONEG), + OPT_STRING(0, "merge-base", + &merge_base, + N_("commit"), + N_("specify a merge-base for the merge")), OPT_END() }; @@ -529,6 +551,8 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) if (o.mode == MODE_TRIVIAL) die(_("--trivial-merge is incompatible with all other options")); + if (merge_base) + die(_("--merge-base is incompatible with --stdin")); line_termination = '\0'; while (strbuf_getline_lf(&buf, stdin) != EOF) { struct strbuf **split; @@ -538,7 +562,7 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) if (!split[0] || !split[1] || split[2]) die(_("malformed input line: '%s'."), buf.buf); strbuf_rtrim(split[0]); - result = real_merge(&o, split[0]->buf, split[1]->buf, prefix); + result = real_merge(&o, merge_base, split[0]->buf, split[1]->buf, prefix); if (result < 0) die(_("merging cannot continue; got unclean result of %d"), result); strbuf_list_free(split); @@ -581,7 +605,7 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) /* Do the relevant type of merge */ if (o.mode == MODE_REAL) - return real_merge(&o, argv[0], argv[1], prefix); + return real_merge(&o, merge_base, argv[0], argv[1], prefix); else return trivial_merge(argv[0], argv[1], argv[2]); } diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh index cac85591b5..6db96ccbaa 100755 --- a/t/t4301-merge-tree-write-tree.sh +++ b/t/t4301-merge-tree-write-tree.sh @@ -860,4 +860,31 @@ test_expect_success '--stdin with both a successful and a conflicted merge' ' test_cmp expect actual ' +# specify merge-base as parent of branch2 +# git merge-tree --write-tree --merge-base=c2 c1 c3 +# Commit c1: add file1 +# Commit c2: add file2 after c1 +# Commit c3: add file3 after c2 +# Expected: add file3, and file2 does NOT appear + +test_expect_success 'specify merge-base as parent of branch2' ' + # Setup + test_when_finished "rm -rf base-b2-p" && + git init base-b2-p && + test_commit -C base-b2-p c1 file1 && + test_commit -C base-b2-p c2 file2 && + test_commit -C base-b2-p c3 file3 && + + # Testing + TREE_OID=$(git -C base-b2-p merge-tree --write-tree --merge-base=c2 c1 c3) && + + q_to_tab <<-EOF >expect && + 100644 blob $(git -C base-b2-p rev-parse c1:file1)Qfile1 + 100644 blob $(git -C base-b2-p rev-parse c3:file3)Qfile3 + EOF + + git -C base-b2-p ls-tree $TREE_OID >actual && + test_cmp expect actual +' + test_done From 501e3bab99da75eada3e2d6ef5257a3c44dd1ae4 Mon Sep 17 00:00:00 2001 From: Kyle Zhao Date: Fri, 11 Nov 2022 23:45:14 +0000 Subject: [PATCH 2/3] merge-tree.c: allow specifying the merge-base when --stdin is passed The previous commit added a `--merge-base` option in order to allow using a specified merge-base for the merge. Extend the input accepted by `--stdin` to also allow a specified merge-base with each merge requested. For example: printf " -- " | git merge-tree --stdin does a merge of b1 and b2, and uses b3 as the merge-base. Signed-off-by: Kyle Zhao Signed-off-by: Taylor Blau --- Documentation/git-merge-tree.txt | 14 ++++++++++++- builtin/merge-tree.c | 21 +++++++++++++++++-- t/t4301-merge-tree-write-tree.sh | 35 ++++++++++++++++++++++++++++++++ 3 files changed, 67 insertions(+), 3 deletions(-) diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt index d9dacb2ce5..298c133fdb 100644 --- a/Documentation/git-merge-tree.txt +++ b/Documentation/git-merge-tree.txt @@ -66,7 +66,8 @@ OPTIONS --merge-base=:: Instead of finding the merge-bases for and , - specify a merge-base for the merge. + specify a merge-base for the merge. This option is incompatible + with `--stdin`. [[OUTPUT]] OUTPUT @@ -220,6 +221,17 @@ with linkgit:git-merge[1]: * any messages that would have been printed to stdout (the <>) +INPUT FORMAT +------------ +'git merge-tree --stdin' input format is fully text based. Each line +has this format: + + [ -- ] + +If one line is separated by `--`, the string before the separator is +used for specifying a merge-base for the merge and the string after +the separator describes the branches to be merged. + MISTAKES TO AVOID ----------------- diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c index 62c6d43cdb..330f779e8b 100644 --- a/builtin/merge-tree.c +++ b/builtin/merge-tree.c @@ -557,12 +557,29 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) while (strbuf_getline_lf(&buf, stdin) != EOF) { struct strbuf **split; int result; + const char *input_merge_base = NULL; split = strbuf_split(&buf, ' '); - if (!split[0] || !split[1] || split[2]) + if (!split[0] || !split[1]) die(_("malformed input line: '%s'."), buf.buf); strbuf_rtrim(split[0]); - result = real_merge(&o, merge_base, split[0]->buf, split[1]->buf, prefix); + strbuf_rtrim(split[1]); + + /* parse the merge-base */ + if (!strcmp(split[1]->buf, "--")) { + input_merge_base = split[0]->buf; + } + + if (input_merge_base && split[2] && split[3] && !split[4]) { + strbuf_rtrim(split[2]); + strbuf_rtrim(split[3]); + result = real_merge(&o, input_merge_base, split[2]->buf, split[3]->buf, prefix); + } else if (!input_merge_base && !split[2]) { + result = real_merge(&o, NULL, split[0]->buf, split[1]->buf, prefix); + } else { + die(_("malformed input line: '%s'."), buf.buf); + } + if (result < 0) die(_("merging cannot continue; got unclean result of %d"), result); strbuf_list_free(split); diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh index 6db96ccbaa..a8983a0edc 100755 --- a/t/t4301-merge-tree-write-tree.sh +++ b/t/t4301-merge-tree-write-tree.sh @@ -860,6 +860,13 @@ test_expect_success '--stdin with both a successful and a conflicted merge' ' test_cmp expect actual ' + +test_expect_success '--merge-base is incompatible with --stdin' ' + test_must_fail git merge-tree --merge-base=side1 --stdin 2>expect && + + grep "^fatal: --merge-base is incompatible with --stdin" expect +' + # specify merge-base as parent of branch2 # git merge-tree --write-tree --merge-base=c2 c1 c3 # Commit c1: add file1 @@ -887,4 +894,32 @@ test_expect_success 'specify merge-base as parent of branch2' ' test_cmp expect actual ' +# Since the earlier tests have verified that individual merge-tree calls +# are doing the right thing, this test case is only used to verify that +# we can also trigger merges via --stdin, and that when we do we get +# the same answer as running a bunch of separate merges. + +test_expect_success 'check the input format when --stdin is passed' ' + test_when_finished "rm -rf repo" && + git init repo && + test_commit -C repo c1 && + test_commit -C repo c2 && + test_commit -C repo c3 && + printf "c1 c3\nc2 -- c1 c3\nc2 c3" | git -C repo merge-tree --stdin >actual && + + printf "1\0" >expect && + git -C repo merge-tree --write-tree -z c1 c3 >>expect && + printf "\0" >>expect && + + printf "1\0" >>expect && + git -C repo merge-tree --write-tree -z --merge-base=c2 c1 c3 >>expect && + printf "\0" >>expect && + + printf "1\0" >>expect && + git -C repo merge-tree --write-tree -z c2 c3 >>expect && + printf "\0" >>expect && + + test_cmp expect actual +' + test_done From 4cc9eb338d8773b4c3909368445404745f94ce69 Mon Sep 17 00:00:00 2001 From: Kyle Zhao Date: Thu, 24 Nov 2022 03:37:06 +0000 Subject: [PATCH 3/3] docs: fix description of the `--merge-base` option Signed-off-by: Kyle Zhao Signed-off-by: Junio C Hamano --- Documentation/git-merge-tree.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt index 298c133fdb..88ee942101 100644 --- a/Documentation/git-merge-tree.txt +++ b/Documentation/git-merge-tree.txt @@ -66,8 +66,8 @@ OPTIONS --merge-base=:: Instead of finding the merge-bases for and , - specify a merge-base for the merge. This option is incompatible - with `--stdin`. + specify a merge-base for the merge, and specifying multiple bases is + currently not supported. This option is incompatible with `--stdin`. [[OUTPUT]] OUTPUT