general improvements
[gitweb.git] / builtin / rebase.c
index 670096c065f5f5fa8cb57c642cd759111b010988..4a20582e724b00a565ee8b0fd05137a11b27568c 100644 (file)
@@ -29,8 +29,8 @@
 #include "rebase-interactive.h"
 
 static char const * const builtin_rebase_usage[] = {
-       N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
-               "[<upstream>] [<branch>]"),
+       N_("git rebase [-i] [options] [--exec <cmd>] "
+               "[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
                "--root [<branch>]"),
        N_("git rebase --continue | --abort | --skip | --edit-todo"),
@@ -62,7 +62,7 @@ struct rebase_options {
        const char *onto_name;
        const char *revisions;
        const char *switch_to;
-       int root;
+       int root, root_with_onto;
        struct object_id *squash_onto;
        struct commit *restrict_revision;
        int dont_finish_rebase;
@@ -374,6 +374,7 @@ static int run_rebase_interactive(struct rebase_options *opts,
        flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
        flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
        flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
+       flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
        flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 
        switch (command) {
@@ -1260,24 +1261,44 @@ static int is_linear_history(struct commit *from, struct commit *to)
        return 1;
 }
 
-static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
-                           struct object_id *merge_base)
+static int can_fast_forward(struct commit *onto, struct commit *upstream,
+                           struct commit *restrict_revision,
+                           struct object_id *head_oid, struct object_id *merge_base)
 {
        struct commit *head = lookup_commit(the_repository, head_oid);
-       struct commit_list *merge_bases;
-       int res;
+       struct commit_list *merge_bases = NULL;
+       int res = 0;
 
        if (!head)
-               return 0;
+               goto done;
 
        merge_bases = get_merge_bases(onto, head);
-       if (merge_bases && !merge_bases->next) {
-               oidcpy(merge_base, &merge_bases->item->object.oid);
-               res = oideq(merge_base, &onto->object.oid);
-       } else {
+       if (!merge_bases || merge_bases->next) {
                oidcpy(merge_base, &null_oid);
-               res = 0;
+               goto done;
        }
+
+       oidcpy(merge_base, &merge_bases->item->object.oid);
+       if (!oideq(merge_base, &onto->object.oid))
+               goto done;
+
+       if (restrict_revision && !oideq(&restrict_revision->object.oid, merge_base))
+               goto done;
+
+       if (!upstream)
+               goto done;
+
+       free_commit_list(merge_bases);
+       merge_bases = get_merge_bases(upstream, head);
+       if (!merge_bases || merge_bases->next)
+               goto done;
+
+       if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
+               goto done;
+
+       res = 1;
+
+done:
        free_commit_list(merge_bases);
        return res && is_linear_history(onto, head);
 }
@@ -1376,6 +1397,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
        struct rebase_options options = REBASE_OPTIONS_INIT;
        const char *branch_name;
        int ret, flags, total_argc, in_progress = 0;
+       int keep_base = 0;
        int ok_to_skip_pre_rebase = 0;
        struct strbuf msg = STRBUF_INIT;
        struct strbuf revisions = STRBUF_INIT;
@@ -1394,6 +1416,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                OPT_STRING(0, "onto", &options.onto_name,
                           N_("revision"),
                           N_("rebase onto given branch instead of upstream")),
+               OPT_BOOL(0, "keep-base", &keep_base,
+                        N_("use the merge-base of upstream and branch as the current base")),
                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
                         N_("allow pre-rebase hook to run")),
                OPT_NEGBIT('q', "quiet", &options.flags,
@@ -1547,6 +1571,13 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                warning(_("git rebase --preserve-merges is deprecated. "
                          "Use --rebase-merges instead."));
 
+       if (keep_base) {
+               if (options.onto_name)
+                       die(_("cannot combine '--keep-base' with '--onto'"));
+               if (options.root)
+                       die(_("cannot combine '--keep-base' with '--root'"));
+       }
+
        if (action != ACTION_NONE && !in_progress)
                die(_("No rebase in progress?"));
        setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
@@ -1833,15 +1864,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                              "'--reschedule-failed-exec'"));
        }
 
-       if (options.rebase_merges) {
-               if (strategy_options.nr)
-                       die(_("cannot combine '--rebase-merges' with "
-                             "'--strategy-option'"));
-               if (options.strategy)
-                       die(_("cannot combine '--rebase-merges' with "
-                             "'--strategy'"));
-       }
-
        if (!options.root) {
                if (argc < 1) {
                        struct branch *branch;
@@ -1872,7 +1894,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                        options.squash_onto = &squash_onto;
                        options.onto_name = squash_onto_name =
                                xstrdup(oid_to_hex(&squash_onto));
-               }
+               } else
+                       options.root_with_onto = 1;
+
                options.upstream_name = NULL;
                options.upstream = NULL;
                if (argc > 1)
@@ -1882,12 +1906,22 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
        }
 
        /* Make sure the branch to rebase onto is valid. */
-       if (!options.onto_name)
+       if (keep_base) {
+               strbuf_reset(&buf);
+               strbuf_addstr(&buf, options.upstream_name);
+               strbuf_addstr(&buf, "...");
+               options.onto_name = xstrdup(buf.buf);
+       } else if (!options.onto_name)
                options.onto_name = options.upstream_name;
        if (strstr(options.onto_name, "...")) {
-               if (get_oid_mb(options.onto_name, &merge_base) < 0)
-                       die(_("'%s': need exactly one merge base"),
-                           options.onto_name);
+               if (get_oid_mb(options.onto_name, &merge_base) < 0) {
+                       if (keep_base)
+                               die(_("'%s': need exactly one merge base with branch"),
+                                   options.upstream_name);
+                       else
+                               die(_("'%s': need exactly one merge base"),
+                                   options.onto_name);
+               }
                options.onto = lookup_commit_or_die(&merge_base,
                                                    options.onto_name);
        } else {
@@ -1968,9 +2002,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                                state_dir_path("autostash", &options);
                        struct child_process stash = CHILD_PROCESS_INIT;
                        struct object_id oid;
-                       struct commit *head =
-                               lookup_commit_reference(the_repository,
-                                                       &options.orig_head);
 
                        argv_array_pushl(&stash.args,
                                         "stash", "create", "autostash", NULL);
@@ -1991,17 +2022,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                                    options.state_dir);
                        write_file(autostash, "%s", oid_to_hex(&oid));
                        printf(_("Created autostash: %s\n"), buf.buf);
-                       if (reset_head(&head->object.oid, "reset --hard",
+                       if (reset_head(NULL, "reset --hard",
                                       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
                                die(_("could not reset --hard"));
-                       printf(_("HEAD is now at %s"),
-                              find_unique_abbrev(&head->object.oid,
-                                                 DEFAULT_ABBREV));
-                       strbuf_reset(&buf);
-                       pp_commit_easy(CMIT_FMT_ONELINE, head, &buf);
-                       if (buf.len > 0)
-                               printf(" %s", buf.buf);
-                       putchar('\n');
 
                        if (discard_index(the_repository->index) < 0 ||
                                repo_read_index(the_repository) < 0)
@@ -2022,13 +2045,13 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
        /*
         * Check if we are already based on onto with linear history,
-        * but this should be done only when upstream and onto are the same
-        * and if this is not an interactive rebase.
+        * in which case we could fast-forward without replacing the commits
+        * with new commits recreated by replaying their changes. This
+        * optimization must not be done if this is an interactive rebase.
         */
-       if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
-           !is_interactive(&options) && !options.restrict_revision &&
-           options.upstream &&
-           !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
+       if (can_fast_forward(options.onto, options.upstream, options.restrict_revision,
+                   &options.orig_head, &merge_base) &&
+           !is_interactive(&options)) {
                int flag;
 
                if (!(options.flags & REBASE_FORCE)) {