merge-tree: accept 3 trees as arguments

When specifying a merge base explicitly, there is actually no good
reason why the inputs need to be commits: that's only needed if the
merge base has to be deduced from the commit graph.

This commit is best viewed with `--color-moved
--color-moved-ws=allow-indentation-change`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt
index b50acace3bc367ad7b73d2da10252e6b5f2e0d07..dd388fa21d5a51d1b6c3aca1b1d18b98f69a4f88 100644 (file)
--- a/Documentation/git-merge-tree.txt
+++ b/Documentation/git-merge-tree.txt
@@ -64,10 +64,13 @@ OPTIONS
        share no common history.  This flag can be given to override that
        check and make the merge proceed anyway.
 
---merge-base=<commit>::
+--merge-base=<tree-ish>::
        Instead of finding the merge-bases for <branch1> and <branch2>,
        specify a merge-base for the merge, and specifying multiple bases is
        currently not supported. This option is incompatible with `--stdin`.
++
+As the merge-base is provided directly, <branch1> and <branch2> do not need
+to specify commits; trees are enough.
 
 [[OUTPUT]]
 OUTPUT

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index a35e0452d6672594da29623e8934256f37784549..2d4ce5b388699ec8ec4aa658d04de0abaa6f1557 100644 (file)
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -430,35 +430,43 @@ static int real_merge(struct merge_tree_options *o,
        struct merge_options opt;
 
        copy_merge_options(&opt, &o->merge_options);
-       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"));
-
        opt.show_rename_progress = 0;
 
        opt.branch1 = branch1;
        opt.branch2 = branch2;
 
        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);
+               /*
+                * We actually only need the trees because we already
+                * have a merge base.
+                */
+               struct object_id base_oid, head_oid, merge_oid;
+
+               if (repo_get_oid_treeish(the_repository, merge_base, &base_oid))
+                       die(_("could not parse as tree '%s'"), merge_base);
+               base_tree = parse_tree_indirect(&base_oid);
+               if (repo_get_oid_treeish(the_repository, branch1, &head_oid))
+                       die(_("could not parse as tree '%s'"), branch1);
+               parent1_tree = parse_tree_indirect(&head_oid);
+               if (repo_get_oid_treeish(the_repository, branch2, &merge_oid))
+                       die(_("could not parse as tree '%s'"), branch2);
+               parent2_tree = parse_tree_indirect(&merge_oid);
 
                opt.ancestor = merge_base;
-               base_tree = repo_get_commit_tree(the_repository, base_commit);
-               parent1_tree = repo_get_commit_tree(the_repository, parent1);
-               parent2_tree = repo_get_commit_tree(the_repository, parent2);
                merge_incore_nonrecursive(&opt, base_tree, parent1_tree, parent2_tree, &result);
        } else {
+               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"));
+
                /*
                 * Get the merge bases, in reverse order; see comment above
                 * merge_incore_recursive in merge-ort.h

diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index b2c8a43fce311570e358d77a3b062228adcbbf68..7d0fa74da74c855a7114629b634f7ea92ee0427a 100755 (executable)
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -945,4 +945,10 @@ test_expect_success 'check the input format when --stdin is passed' '
        test_cmp expect actual
 '
 
+test_expect_success '--merge-base with tree OIDs' '
+       git merge-tree --merge-base=side1^ side1 side3 >with-commits &&
+       git merge-tree --merge-base=side1^^{tree} side1^{tree} side3^{tree} >with-trees &&
+       test_cmp with-commits with-trees
+'
+
 test_done