Hi, On Fri, Oct 28, 2022 at 8:42 PM Kyle Zhao via GitGitGadget <gitgitgadget@xxxxxxxxx> wrote: > > From: Kyle Zhao <kylezhao@xxxxxxxxxxx> > > 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 <kylezhao@xxxxxxxxxxx> > --- > merge-tree: allow specifying a base commit when --write-tree is passed > > Thanks for Elijah's work. I'm very excited that merge-ort is integrated > into the git merge-tree, which means that we can use merge-ort in bare > repositories to optimize merge performance. > > In this patch, I introduce a new --merge-base=<commit> option to allow > callers to specify a merge-base for the merge. This may allow users to > implement git cherry-pick and git rebase in bare repositories with git > merge-tree cmd. > > Changes since v1: > > * Changed merge_incore_recursive() to merge_incore_nonrecursive() when > merge-base is specified. > * Fixed c style problem. > * Moved commit lookup/die logic out to the parsing logic in > cmd_merge_tree(). > * use test_commit for test > > Changes since v2: > > * commit message > * Rebased on top of en/merge-tree-sequence. > * Set opt.ancestor to o->merge_base. Because opt.ancestor is a *char. > To make it easier to pass parameters, I moved > lookup_commit_reference_by_name() to real_ merge() again. > * Added test comment. > > Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1397%2Fkeyu98%2Fkz%2Fmerge-tree-option-merge-base-v3 > Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1397/keyu98/kz/merge-tree-option-merge-base-v3 > Pull-Request: https://github.com/gitgitgadget/git/pull/1397 > [...] > Documentation/git-merge-tree.txt | 4 ++++ > builtin/merge-tree.c | 39 ++++++++++++++++++++++++-------- > t/t4301-merge-tree-write-tree.sh | 30 ++++++++++++++++++++++++ > 3 files changed, 64 insertions(+), 9 deletions(-) > > diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt > index 04bcc416e6e..d9dacb2ce54 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=<commit>:: > + Instead of finding the merge-bases for <branch1> and <branch2>, > + specify a merge-base for the merge. > + > [[OUTPUT]] > OUTPUT > ------ > diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c > index fe853aa8f91..cd25aac6ba6 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" > @@ -403,6 +404,7 @@ struct merge_tree_options { > int show_messages; > int name_only; > int use_stdin; > + const char *merge_base; > }; > > static int real_merge(struct merge_tree_options *o, > @@ -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 (o->merge_base) { > + struct commit *base_commit; > + struct tree *base_tree, *parent1_tree, *parent2_tree; > + > + base_commit = lookup_commit_reference_by_name(o->merge_base); > + if (!base_commit) > + die(_("could not lookup commit %s"), o->merge_base); > + > + opt.ancestor = o->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")); > > @@ -515,6 +532,10 @@ 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", > + &o.merge_base, > + N_("commit"), > + N_("specify a merge-base for the merge")), > OPT_END() > }; > > diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh > index cac85591b52..5b0073d3dcd 100755 > --- a/t/t4301-merge-tree-write-tree.sh > +++ b/t/t4301-merge-tree-write-tree.sh > @@ -860,4 +860,34 @@ 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 > + git init base-b2-p && ( > + cd base-b2-p && > + test_commit c1 file1 && > + test_commit c2 file2 && > + test_commit c3 file3 > + ) && > + # Testing > + ( > + cd base-b2-p && > + TREE_OID=$(git merge-tree --write-tree --merge-base=c2 c1 c3) && > + > + q_to_tab <<-EOF >expect && > + 100644 blob $(git rev-parse c1:file1)Qfile1 > + 100644 blob $(git rev-parse c3:file3)Qfile3 > + EOF > + > + git ls-tree $TREE_OID >actual && > + test_cmp expect actual > + ) > +' > + > test_done > > base-commit: ec1edbcb56ac05e9980299b05924c5c1b51d68b4 This looks pretty good; thanks for the many changes. One thing is still missing: you are now building on a commit that adds a --stdin option to merge-tree, which allows the user to specify what to merge on stdin rather than via other arguments on the command line. Since you're making merge-tree support specified merge base(s), it should also support that in conjunction with --stdin. So, see the "/* Handle stdin */" block and adjust it appropriately. Once you do that, I think your series will be good to go.
