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>
---
Documentation/git-merge-tree.txt | 4 +++
builtin/merge-tree.c | 46 ++++++++++++++++++++++++--------
t/t4301-merge-tree-write-tree.sh | 30 +++++++++++++++++++++
3 files changed, 69 insertions(+), 11 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..62c6d43cdb9 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] [<options>] <branch1> <branch2>"),
@@ -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 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
--
gitgitgadget
