merge-tree: add -X strategy option

Add merge strategy option to produce more customizable merge result such
as automatically resolving conflicts.

Signed-off-by: Tang Yuyi <winglovet@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 0de42aecf4babf5d1cae19aa81e7d46676c636d1..7024b5ce2e4d17aec3e2dcc59069ad4c60061818 100644 (file)
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -18,6 +18,7 @@
 #include "quote.h"
 #include "tree.h"
 #include "config.h"
+#include "strvec.h"
 
 static int line_termination = '\n';
 
@@ -414,6 +415,7 @@ struct merge_tree_options {
        int show_messages;
        int name_only;
        int use_stdin;
+       struct merge_options merge_options;
 };
 
 static int real_merge(struct merge_tree_options *o,
@@ -423,7 +425,7 @@ static int real_merge(struct merge_tree_options *o,
 {
        struct commit *parent1, *parent2;
        struct commit_list *merge_bases = NULL;
-       struct merge_options opt;
+       struct merge_options opt = o->merge_options;
        struct merge_result result = { 0 };
        int show_messages = o->show_messages;
 
@@ -437,8 +439,6 @@ static int real_merge(struct merge_tree_options *o,
                help_unknown_ref(branch2, "merge-tree",
                                 _("not something we can merge"));
 
-       init_merge_options(&opt, the_repository);
-
        opt.show_rename_progress = 0;
 
        opt.branch1 = branch1;
@@ -513,6 +513,7 @@ static int real_merge(struct merge_tree_options *o,
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
        struct merge_tree_options o = { .show_messages = -1 };
+       struct strvec xopts = STRVEC_INIT;
        int expected_remaining_argc;
        int original_argc;
        const char *merge_base = NULL;
@@ -548,14 +549,25 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
                           &merge_base,
                           N_("commit"),
                           N_("specify a merge-base for the merge")),
+               OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
+                       N_("option for selected merge strategy")),
                OPT_END()
        };
 
+       /* Init merge options */
+       init_merge_options(&o.merge_options, the_repository);
+
        /* Parse arguments */
        original_argc = argc - 1; /* ignoring argv[0] */
        argc = parse_options(argc, argv, prefix, mt_options,
                             merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
+       if (xopts.nr && o.mode == MODE_TRIVIAL)
+               die(_("--trivial-merge is incompatible with all other options"));
+       for (int x = 0; x < xopts.nr; x++)
+               if (parse_merge_opt(&o.merge_options, xopts.v[x]))
+                       die(_("unknown strategy option: -X%s"), xopts.v[x]);
+
        /* Handle --stdin */
        if (o.use_stdin) {
                struct strbuf buf = STRBUF_INIT;

diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index 250f721795b5bd2ecba3090b7e181c50673540aa..b2c8a43fce311570e358d77a3b062228adcbbf68 100755 (executable)
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -22,6 +22,7 @@ test_expect_success setup '
        git branch side1 &&
        git branch side2 &&
        git branch side3 &&
+       git branch side4 &&
 
        git checkout side1 &&
        test_write_lines 1 2 3 4 5 6 >numbers &&
@@ -46,6 +47,13 @@ test_expect_success setup '
        test_tick &&
        git commit -m rename-numbers &&
 
+       git checkout side4 &&
+       test_write_lines 0 1 2 3 4 5 >numbers &&
+       echo yo >greeting &&
+       git add numbers greeting &&
+       test_tick &&
+       git commit -m other-content-modifications &&
+
        git switch --orphan unrelated &&
        >something-else &&
        git add something-else &&
@@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
        test_cmp expect actual
 '
 
+test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
+       git checkout side1^0 &&
+
+       # make sure merge conflict exists
+       test_must_fail git merge side4 &&
+       git merge --abort &&
+
+       git merge -X ours side4 &&
+       git rev-parse HEAD^{tree} >expected &&
+
+       git merge-tree -X ours side1 side4 >actual &&
+
+       test_cmp expected actual
+'
+
 test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
        # Mis-spell with single "s" instead of double "s"
        test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&