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
Range-diff vs v2:
1: ab4e5d5ad08 ! 1: 554cbde49e8 merge-tree.c: add --merge-base=<commit> option
@@ Commit message
git merge-tree --write-tree --merge-base=branch^ HEAD branch
- It would cherry-pick the commit at the tip of the branch on top of the
- current commit even if the repository is bare.
+ 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>
@@ builtin/merge-tree.c
#include "merge-ort.h"
#include "object-store.h"
@@ builtin/merge-tree.c: struct merge_tree_options {
- int allow_unrelated_histories;
int show_messages;
int name_only;
-+ const struct commit *base_commit;
+ int use_stdin;
++ const char *merge_base;
};
static int real_merge(struct merge_tree_options *o,
@@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
- if (!merge_bases && !o->allow_unrelated_histories)
- die(_("refusing to merge unrelated histories"));
- merge_bases = reverse_commit_list(merge_bases);
-+ if (o->base_commit) {
++ if (o->merge_base) {
++ struct commit *base_commit;
+ struct tree *base_tree, *parent1_tree, *parent2_tree;
+
-+ opt.ancestor = "specified merge base";
-+ base_tree = get_commit_tree(o->base_commit);
++ 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);
@@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
if (result.clean < 0)
die(_("failure to merge"));
-@@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
-
- int cmd_merge_tree(int argc, const char **argv, const char *prefix)
- {
-+ const char *merge_base = NULL;
- struct merge_tree_options o = { .show_messages = -1 };
- int expected_remaining_argc;
- int original_argc;
@@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char *prefix)
- &o.allow_unrelated_histories,
- N_("allow merging unrelated histories"),
+ &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")),
++ &o.merge_base,
++ N_("commit"),
++ N_("specify a merge-base for the merge")),
OPT_END()
};
-@@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char *prefix)
- usage_with_options(merge_tree_usage, mt_options);
-
- /* Do the relevant type of merge */
-- if (o.mode == MODE_REAL)
-+ if (o.mode == MODE_REAL) {
-+ if (merge_base) {
-+ o.base_commit = lookup_commit_reference_by_name(merge_base);
-+ if (!o.base_commit)
-+ die(_("could not lookup commit %s"), merge_base);
-+ }
- return real_merge(&o, argv[0], argv[1], prefix);
-+ }
- else
- return trivial_merge(argv[0], argv[1], argv[2]);
- }
## t/t4301-merge-tree-write-tree.sh ##
-@@ t/t4301-merge-tree-write-tree.sh: test_expect_success SANITY 'merge-ort fails gracefully in a read-only repository
- test_must_fail git -C read-only merge-tree side1 side2
+@@ t/t4301-merge-tree-write-tree.sh: 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 && (
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
--
gitgitgadget
