rebase: teach rebase --keep-base

[thirdparty/git.git] / builtin / rebase.c

diff --git a/builtin/rebase.c b/builtin/rebase.c
index 7ef9095e7c32f56e45392afaee5539642681bca6..27d5c4e19d1c16491060aff4a05500917fb28be1 100644 (file)
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -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"),
@@ -1396,6 +1396,7 @@ 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;
@@ -1414,6 +1415,8 @@ 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,
@@ -1567,6 +1570,13 @@ 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);
@@ -1902,12 +1912,22 @@ 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 {