Merge branch 'ct/advise-push-default' into maint
[gitweb.git] / builtin / merge.c
index 08e01e8a60d7d7f9c60e9e7a3a2f8b4d66c12ce3..470fc57c5d6ceabedbd866a5db35d3123a764af0 100644 (file)
@@ -52,7 +52,6 @@ static int fast_forward_only, option_edit = -1;
 static int allow_trivial = 1, have_message;
 static int overwrite_ignore = 1;
 static struct strbuf merge_msg = STRBUF_INIT;
-static struct commit_list *remoteheads;
 static struct strategy **use_strategies;
 static size_t use_strategies_nr, use_strategies_alloc;
 static const char **xopts;
@@ -318,7 +317,7 @@ static void finish_up_to_date(const char *msg)
        drop_save();
 }
 
-static void squash_message(struct commit *commit)
+static void squash_message(struct commit *commit, struct commit_list *remoteheads)
 {
        struct rev_info rev;
        struct strbuf out = STRBUF_INIT;
@@ -366,6 +365,7 @@ static void squash_message(struct commit *commit)
 }
 
 static void finish(struct commit *head_commit,
+                  struct commit_list *remoteheads,
                   const unsigned char *new_head, const char *msg)
 {
        struct strbuf reflog_message = STRBUF_INIT;
@@ -380,7 +380,7 @@ static void finish(struct commit *head_commit,
                        getenv("GIT_REFLOG_ACTION"), msg);
        }
        if (squash) {
-               squash_message(head_commit);
+               squash_message(head_commit, remoteheads);
        } else {
                if (verbosity >= 0 && !merge_msg.len)
                        printf(_("No merge message -- not updating HEAD\n"));
@@ -683,6 +683,7 @@ int try_merge_command(const char *strategy, size_t xopts_nr,
 }
 
 static int try_merge_strategy(const char *strategy, struct commit_list *common,
+                             struct commit_list *remoteheads,
                              struct commit *head, const char *head_arg)
 {
        int index_fd;
@@ -876,14 +877,14 @@ static void read_merge_msg(struct strbuf *msg)
                die_errno(_("Could not read from '%s'"), filename);
 }
 
-static void write_merge_state(void);
-static void abort_commit(const char *err_msg)
+static void write_merge_state(struct commit_list *);
+static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
 {
        if (err_msg)
                error("%s", err_msg);
        fprintf(stderr,
                _("Not committing merge; use 'git commit' to complete the merge.\n"));
-       write_merge_state();
+       write_merge_state(remoteheads);
        exit(1);
 }
 
@@ -894,7 +895,7 @@ N_("Please enter a commit message to explain why this merge is necessary,\n"
    "Lines starting with '#' will be ignored, and an empty message aborts\n"
    "the commit.\n");
 
-static void prepare_to_commit(void)
+static void prepare_to_commit(struct commit_list *remoteheads)
 {
        struct strbuf msg = STRBUF_INIT;
        const char *comment = _(merge_editor_comment);
@@ -907,18 +908,18 @@ static void prepare_to_commit(void)
                 git_path("MERGE_MSG"), "merge", NULL, NULL);
        if (0 < option_edit) {
                if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
-                       abort_commit(NULL);
+                       abort_commit(remoteheads, NULL);
        }
        read_merge_msg(&msg);
        stripspace(&msg, 0 < option_edit);
        if (!msg.len)
-               abort_commit(_("Empty commit message."));
+               abort_commit(remoteheads, _("Empty commit message."));
        strbuf_release(&merge_msg);
        strbuf_addbuf(&merge_msg, &msg);
        strbuf_release(&msg);
 }
 
-static int merge_trivial(struct commit *head)
+static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 {
        unsigned char result_tree[20], result_commit[20];
        struct commit_list *parent = xmalloc(sizeof(*parent));
@@ -929,45 +930,37 @@ static int merge_trivial(struct commit *head)
        parent->next = xmalloc(sizeof(*parent->next));
        parent->next->item = remoteheads->item;
        parent->next->next = NULL;
-       prepare_to_commit();
+       prepare_to_commit(remoteheads);
        if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL,
                        sign_commit))
                die(_("failed to write commit object"));
-       finish(head, result_commit, "In-index merge");
+       finish(head, remoteheads, result_commit, "In-index merge");
        drop_save();
        return 0;
 }
 
 static int finish_automerge(struct commit *head,
+                           int head_subsumed,
                            struct commit_list *common,
+                           struct commit_list *remoteheads,
                            unsigned char *result_tree,
                            const char *wt_strategy)
 {
-       struct commit_list *parents = NULL, *j;
+       struct commit_list *parents = NULL;
        struct strbuf buf = STRBUF_INIT;
        unsigned char result_commit[20];
 
        free_commit_list(common);
-       if (allow_fast_forward) {
-               parents = remoteheads;
+       parents = remoteheads;
+       if (!head_subsumed || !allow_fast_forward)
                commit_list_insert(head, &parents);
-               parents = reduce_heads(parents);
-       } else {
-               struct commit_list **pptr = &parents;
-
-               pptr = &commit_list_insert(head,
-                               pptr)->next;
-               for (j = remoteheads; j; j = j->next)
-                       pptr = &commit_list_insert(j->item, pptr)->next;
-       }
        strbuf_addch(&merge_msg, '\n');
-       prepare_to_commit();
-       free_commit_list(remoteheads);
+       prepare_to_commit(remoteheads);
        if (commit_tree(&merge_msg, result_tree, parents, result_commit,
                        NULL, sign_commit))
                die(_("failed to write commit object"));
        strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
-       finish(head, result_commit, buf.buf);
+       finish(head, remoteheads, result_commit, buf.buf);
        strbuf_release(&buf);
        drop_save();
        return 0;
@@ -1072,7 +1065,7 @@ static int setup_with_upstream(const char ***argv)
        return i;
 }
 
-static void write_merge_state(void)
+static void write_merge_state(struct commit_list *remoteheads)
 {
        const char *filename;
        int fd;
@@ -1137,6 +1130,39 @@ static int default_edit_option(void)
                st_stdin.st_mode == st_stdout.st_mode);
 }
 
+static struct commit_list *collect_parents(struct commit *head_commit,
+                                          int *head_subsumed,
+                                          int argc, const char **argv)
+{
+       int i;
+       struct commit_list *remoteheads = NULL, *parents, *next;
+       struct commit_list **remotes = &remoteheads;
+
+       if (head_commit)
+               remotes = &commit_list_insert(head_commit, remotes)->next;
+       for (i = 0; i < argc; i++) {
+               struct commit *commit = get_merge_parent(argv[i]);
+               if (!commit)
+                       die(_("%s - not something we can merge"), argv[i]);
+               remotes = &commit_list_insert(commit, remotes)->next;
+       }
+       *remotes = NULL;
+
+       parents = reduce_heads(remoteheads);
+
+       *head_subsumed = 1; /* we will flip this to 0 when we find it */
+       for (remoteheads = NULL, remotes = &remoteheads;
+            parents;
+            parents = next) {
+               struct commit *commit = parents->item;
+               next = parents->next;
+               if (commit == head_commit)
+                       *head_subsumed = 0;
+               else
+                       remotes = &commit_list_insert(commit, remotes)->next;
+       }
+       return remoteheads;
+}
 
 int cmd_merge(int argc, const char **argv, const char *prefix)
 {
@@ -1146,11 +1172,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
        struct commit *head_commit;
        struct strbuf buf = STRBUF_INIT;
        const char *head_arg;
-       int flag, i, ret = 0;
+       int flag, i, ret = 0, head_subsumed;
        int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
        struct commit_list *common = NULL;
        const char *best_strategy = NULL, *wt_strategy = NULL;
-       struct commit_list **remotes = &remoteheads;
+       struct commit_list *remoteheads, *p;
        void *branch_to_free;
 
        if (argc == 2 && !strcmp(argv[1], "-h"))
@@ -1255,6 +1281,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                head_arg = argv[1];
                argv += 2;
                argc -= 2;
+               remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
        } else if (!head_commit) {
                struct commit *remote_head;
                /*
@@ -1270,7 +1297,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                if (!allow_fast_forward)
                        die(_("Non-fast-forward commit does not make sense into "
                            "an empty head"));
-               remote_head = get_merge_parent(argv[0]);
+               remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
+               remote_head = remoteheads->item;
                if (!remote_head)
                        die(_("%s - not something we can merge"), argv[0]);
                read_empty(remote_head->object.sha1, 0);
@@ -1288,8 +1316,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                 * the standard merge summary message to be appended
                 * to the given message.
                 */
-               for (i = 0; i < argc; i++)
-                       merge_name(argv[i], &merge_names);
+               remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
+               for (p = remoteheads; p; p = p->next)
+                       merge_name(merge_remote_util(p->item)->name, &merge_names);
 
                if (!have_message || shortlog_len) {
                        struct fmt_merge_msg_opts opts;
@@ -1308,19 +1337,16 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                        builtin_merge_options);
 
        strbuf_addstr(&buf, "merge");
-       for (i = 0; i < argc; i++)
-               strbuf_addf(&buf, " %s", argv[i]);
+       for (p = remoteheads; p; p = p->next)
+               strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
        setenv("GIT_REFLOG_ACTION", buf.buf, 0);
        strbuf_reset(&buf);
 
-       for (i = 0; i < argc; i++) {
-               struct commit *commit = get_merge_parent(argv[i]);
-               if (!commit)
-                       die(_("%s - not something we can merge"), argv[i]);
-               remotes = &commit_list_insert(commit, remotes)->next;
+       for (p = remoteheads; p; p = p->next) {
+               struct commit *commit = p->item;
                strbuf_addf(&buf, "GITHEAD_%s",
                            sha1_to_hex(commit->object.sha1));
-               setenv(buf.buf, argv[i], 1);
+               setenv(buf.buf, merge_remote_util(commit)->name, 1);
                strbuf_reset(&buf);
                if (!fast_forward_only &&
                    merge_remote_util(commit) &&
@@ -1333,7 +1359,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                option_edit = default_edit_option();
 
        if (!use_strategies) {
-               if (!remoteheads->next)
+               if (!remoteheads)
+                       ; /* already up-to-date */
+               else if (!remoteheads->next)
                        add_strategies(pull_twohead, DEFAULT_TWOHEAD);
                else
                        add_strategies(pull_octopus, DEFAULT_OCTOPUS);
@@ -1346,7 +1374,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                        allow_trivial = 0;
        }
 
-       if (!remoteheads->next)
+       if (!remoteheads)
+               ; /* already up-to-date */
+       else if (!remoteheads->next)
                common = get_merge_bases(head_commit, remoteheads->item, 1);
        else {
                struct commit_list *list = remoteheads;
@@ -1358,10 +1388,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
        update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
                   NULL, 0, DIE_ON_ERR);
 
-       if (!common)
+       if (remoteheads && !common)
                ; /* No common ancestors found. We need a real merge. */
-       else if (!remoteheads->next && !common->next &&
-                       common->item == remoteheads->item) {
+       else if (!remoteheads ||
+                (!remoteheads->next && !common->next &&
+                 common->item == remoteheads->item)) {
                /*
                 * If head can reach all the merge then we are up to date.
                 * but first the most common case of merging one remote.
@@ -1399,7 +1430,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                        goto done;
                }
 
-               finish(head_commit, commit->object.sha1, msg.buf);
+               finish(head_commit, remoteheads, commit->object.sha1, msg.buf);
                drop_save();
                goto done;
        } else if (!remoteheads->next && common->next)
@@ -1421,7 +1452,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                        if (!read_tree_trivial(common->item->object.sha1,
                                               head_commit->object.sha1,
                                               remoteheads->item->object.sha1)) {
-                               ret = merge_trivial(head_commit);
+                               ret = merge_trivial(head_commit, remoteheads);
                                goto done;
                        }
                        printf(_("Nope.\n"));
@@ -1492,7 +1523,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                wt_strategy = use_strategies[i]->name;
 
                ret = try_merge_strategy(use_strategies[i]->name,
-                                        common, head_commit, head_arg);
+                                        common, remoteheads,
+                                        head_commit, head_arg);
                if (!option_commit && !ret) {
                        merge_was_ok = 1;
                        /*
@@ -1534,8 +1566,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
         * auto resolved the merge cleanly.
         */
        if (automerge_was_ok) {
-               ret = finish_automerge(head_commit, common, result_tree,
-                                      wt_strategy);
+               ret = finish_automerge(head_commit, head_subsumed,
+                                      common, remoteheads,
+                                      result_tree, wt_strategy);
                goto done;
        }
 
@@ -1560,13 +1593,14 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                restore_state(head_commit->object.sha1, stash);
                printf(_("Using the %s to prepare resolving by hand.\n"),
                        best_strategy);
-               try_merge_strategy(best_strategy, common, head_commit, head_arg);
+               try_merge_strategy(best_strategy, common, remoteheads,
+                                  head_commit, head_arg);
        }
 
        if (squash)
-               finish(head_commit, NULL, NULL);
+               finish(head_commit, remoteheads, NULL, NULL);
        else
-               write_merge_state();
+               write_merge_state(remoteheads);
 
        if (merge_was_ok)
                fprintf(stderr, _("Automatic merge went well; "