rebase: validate -C<n> and --whitespace=<mode> parameters early
[gitweb.git] / builtin / rebase.c
index c64d46afd53f3e17ddce2e81c53fb5cd47d159eb..571cf899d5b48c87c3c2f1d91d2d94e559bcfd68 100644 (file)
@@ -21,6 +21,7 @@
 #include "diff.h"
 #include "wt-status.h"
 #include "revision.h"
+#include "commit-reach.h"
 #include "rerere.h"
 
 static char const * const builtin_rebase_usage[] = {
@@ -54,7 +55,7 @@ static int use_builtin_rebase(void)
        cp.git_cmd = 1;
        if (capture_command(&cp, &out, 6)) {
                strbuf_release(&out);
-               return 0;
+               return 1;
        }
 
        strbuf_trim(&out);
@@ -76,6 +77,7 @@ struct rebase_options {
        const char *revisions;
        const char *switch_to;
        int root;
+       struct object_id *squash_onto;
        struct commit *restrict_revision;
        int dont_finish_rebase;
        enum {
@@ -85,7 +87,7 @@ struct rebase_options {
                REBASE_FORCE = 1<<3,
                REBASE_INTERACTIVE_EXPLICIT = 1<<4,
        } flags;
-       struct strbuf git_am_opt;
+       struct argv_array git_am_opts;
        const char *action;
        int signoff;
        int allow_rerere_autoupdate;
@@ -97,6 +99,7 @@ struct rebase_options {
        int allow_empty_message;
        int rebase_merges, rebase_cousins;
        char *strategy, *strategy_opts;
+       struct strbuf git_format_patch_opt;
 };
 
 static int is_interactive(struct rebase_options *opts)
@@ -248,8 +251,10 @@ static int apply_autostash(struct rebase_options *opts)
        if (!file_exists(path))
                return 0;
 
-       if (read_one(state_dir_path("autostash", opts), &autostash))
+       if (read_one(path, &autostash))
                return error(_("Could not read '%s'"), path);
+       /* Ensure that the hash is not mistaken for a number */
+       strbuf_addstr(&autostash, "^0");
        argv_array_pushl(&stash_apply.args,
                         "stash", "apply", autostash.buf, NULL);
        stash_apply.git_cmd = 1;
@@ -324,13 +329,93 @@ static void add_var(struct strbuf *buf, const char *name, const char *value)
        }
 }
 
+static const char *resolvemsg =
+N_("Resolve all conflicts manually, mark them as resolved with\n"
+"\"git add/rm <conflicted_files>\", then run \"git rebase --continue\".\n"
+"You can instead skip this commit: run \"git rebase --skip\".\n"
+"To abort and get back to the state before \"git rebase\", run "
+"\"git rebase --abort\".");
+
 static int run_specific_rebase(struct rebase_options *opts)
 {
        const char *argv[] = { NULL, NULL };
-       struct strbuf script_snippet = STRBUF_INIT;
+       struct strbuf script_snippet = STRBUF_INIT, buf = STRBUF_INIT;
        int status;
        const char *backend, *backend_func;
 
+       if (opts->type == REBASE_INTERACTIVE) {
+               /* Run builtin interactive rebase */
+               struct child_process child = CHILD_PROCESS_INIT;
+
+               argv_array_pushf(&child.env_array, "GIT_CHERRY_PICK_HELP=%s",
+                                resolvemsg);
+               if (!(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
+                       argv_array_push(&child.env_array, "GIT_EDITOR=:");
+                       opts->autosquash = 0;
+               }
+
+               child.git_cmd = 1;
+               argv_array_push(&child.args, "rebase--interactive");
+
+               if (opts->action)
+                       argv_array_pushf(&child.args, "--%s", opts->action);
+               if (opts->keep_empty)
+                       argv_array_push(&child.args, "--keep-empty");
+               if (opts->rebase_merges)
+                       argv_array_push(&child.args, "--rebase-merges");
+               if (opts->rebase_cousins)
+                       argv_array_push(&child.args, "--rebase-cousins");
+               if (opts->autosquash)
+                       argv_array_push(&child.args, "--autosquash");
+               if (opts->flags & REBASE_VERBOSE)
+                       argv_array_push(&child.args, "--verbose");
+               if (opts->flags & REBASE_FORCE)
+                       argv_array_push(&child.args, "--no-ff");
+               if (opts->restrict_revision)
+                       argv_array_pushf(&child.args,
+                                        "--restrict-revision=^%s",
+                                        oid_to_hex(&opts->restrict_revision->object.oid));
+               if (opts->upstream)
+                       argv_array_pushf(&child.args, "--upstream=%s",
+                                        oid_to_hex(&opts->upstream->object.oid));
+               if (opts->onto)
+                       argv_array_pushf(&child.args, "--onto=%s",
+                                        oid_to_hex(&opts->onto->object.oid));
+               if (opts->squash_onto)
+                       argv_array_pushf(&child.args, "--squash-onto=%s",
+                                        oid_to_hex(opts->squash_onto));
+               if (opts->onto_name)
+                       argv_array_pushf(&child.args, "--onto-name=%s",
+                                        opts->onto_name);
+               argv_array_pushf(&child.args, "--head-name=%s",
+                                opts->head_name ?
+                                opts->head_name : "detached HEAD");
+               if (opts->strategy)
+                       argv_array_pushf(&child.args, "--strategy=%s",
+                                        opts->strategy);
+               if (opts->strategy_opts)
+                       argv_array_pushf(&child.args, "--strategy-opts=%s",
+                                        opts->strategy_opts);
+               if (opts->switch_to)
+                       argv_array_pushf(&child.args, "--switch-to=%s",
+                                        opts->switch_to);
+               if (opts->cmd)
+                       argv_array_pushf(&child.args, "--cmd=%s", opts->cmd);
+               if (opts->allow_empty_message)
+                       argv_array_push(&child.args, "--allow-empty-message");
+               if (opts->allow_rerere_autoupdate > 0)
+                       argv_array_push(&child.args, "--rerere-autoupdate");
+               else if (opts->allow_rerere_autoupdate == 0)
+                       argv_array_push(&child.args, "--no-rerere-autoupdate");
+               if (opts->gpg_sign_opt)
+                       argv_array_push(&child.args, opts->gpg_sign_opt);
+               if (opts->signoff)
+                       argv_array_push(&child.args, "--signoff");
+
+               status = run_command(&child);
+               goto finished_rebase;
+       }
+
        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
        add_var(&script_snippet, "state_dir", opts->state_dir);
 
@@ -348,7 +433,9 @@ static int run_specific_rebase(struct rebase_options *opts)
                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
        add_var(&script_snippet, "GIT_QUIET",
                opts->flags & REBASE_NO_QUIET ? "" : "t");
-       add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
+       sq_quote_argv_pretty(&buf, opts->git_am_opts.argv);
+       add_var(&script_snippet, "git_am_opt", buf.buf);
+       strbuf_release(&buf);
        add_var(&script_snippet, "verbose",
                opts->flags & REBASE_VERBOSE ? "t" : "");
        add_var(&script_snippet, "diffstat",
@@ -375,16 +462,24 @@ static int run_specific_rebase(struct rebase_options *opts)
                opts->rebase_cousins ? "t" : "");
        add_var(&script_snippet, "strategy", opts->strategy);
        add_var(&script_snippet, "strategy_opts", opts->strategy_opts);
+       add_var(&script_snippet, "rebase_root", opts->root ? "t" : "");
+       add_var(&script_snippet, "squash_onto",
+               opts->squash_onto ? oid_to_hex(opts->squash_onto) : "");
+       add_var(&script_snippet, "git_format_patch_opt",
+               opts->git_format_patch_opt.buf);
+
+       if (is_interactive(opts) &&
+           !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
+               strbuf_addstr(&script_snippet,
+                             "GIT_EDITOR=:; export GIT_EDITOR; ");
+               opts->autosquash = 0;
+       }
 
        switch (opts->type) {
        case REBASE_AM:
                backend = "git-rebase--am";
                backend_func = "git_rebase__am";
                break;
-       case REBASE_INTERACTIVE:
-               backend = "git-rebase--interactive";
-               backend_func = "git_rebase__interactive";
-               break;
        case REBASE_MERGE:
                backend = "git-rebase--merge";
                backend_func = "git_rebase__merge";
@@ -404,8 +499,11 @@ static int run_specific_rebase(struct rebase_options *opts)
        argv[0] = script_snippet.buf;
 
        status = run_command_v_opt(argv, RUN_USING_SHELL);
+finished_rebase:
        if (opts->dont_finish_rebase)
                ; /* do nothing */
+       else if (opts->type == REBASE_INTERACTIVE)
+               ; /* interactive rebase cleans up after itself */
        else if (status == 0) {
                if (!file_exists(state_dir_path("stopped-sha", opts)))
                        finish_rebase(opts);
@@ -427,7 +525,8 @@ static int run_specific_rebase(struct rebase_options *opts)
 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 
 static int reset_head(struct object_id *oid, const char *action,
-                     const char *switch_to_branch, int detach_head)
+                     const char *switch_to_branch, int detach_head,
+                     const char *reflog_orig_head, const char *reflog_head)
 {
        struct object_id head_oid;
        struct tree_desc desc;
@@ -502,20 +601,26 @@ static int reset_head(struct object_id *oid, const char *action,
                old_orig = &oid_old_orig;
        if (!get_oid("HEAD", &oid_orig)) {
                orig = &oid_orig;
-               strbuf_addstr(&msg, "updating ORIG_HEAD");
-               update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
+               if (!reflog_orig_head) {
+                       strbuf_addstr(&msg, "updating ORIG_HEAD");
+                       reflog_orig_head = msg.buf;
+               }
+               update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
                           UPDATE_REFS_MSG_ON_ERR);
        } else if (old_orig)
                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
-       strbuf_setlen(&msg, prefix_len);
-       strbuf_addstr(&msg, "updating HEAD");
+       if (!reflog_head) {
+               strbuf_setlen(&msg, prefix_len);
+               strbuf_addstr(&msg, "updating HEAD");
+               reflog_head = msg.buf;
+       }
        if (!switch_to_branch)
-               ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
+               ret = update_ref(reflog_head, "HEAD", oid, orig, REF_NO_DEREF,
                                 UPDATE_REFS_MSG_ON_ERR);
        else {
                ret = create_symref("HEAD", switch_to_branch, msg.buf);
                if (!ret)
-                       ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
+                       ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
                                         UPDATE_REFS_MSG_ON_ERR);
        }
 
@@ -586,7 +691,7 @@ static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
        merge_bases = get_merge_bases(onto, head);
        if (merge_bases && !merge_bases->next) {
                oidcpy(merge_base, &merge_bases->item->object.oid);
-               res = !oidcmp(merge_base, &onto->object.oid);
+               res = oideq(merge_base, &onto->object.oid);
        } else {
                oidcpy(merge_base, &null_oid);
                res = 0;
@@ -618,14 +723,45 @@ static int parse_opt_interactive(const struct option *opt, const char *arg,
        return 0;
 }
 
+static void NORETURN error_on_missing_default_upstream(void)
+{
+       struct branch *current_branch = branch_get(NULL);
+
+       printf(_("%s\n"
+                "Please specify which branch you want to rebase against.\n"
+                "See git-rebase(1) for details.\n"
+                "\n"
+                "    git rebase '<branch>'\n"
+                "\n"),
+               current_branch ? _("There is no tracking information for "
+                       "the current branch.") :
+                       _("You are not currently on a branch."));
+
+       if (current_branch) {
+               const char *remote = current_branch->remote_name;
+
+               if (!remote)
+                       remote = _("<remote>");
+
+               printf(_("If you wish to set tracking information for this "
+                        "branch you can do so with:\n"
+                        "\n"
+                        "    git branch --set-upstream-to=%s/<branch> %s\n"
+                        "\n"),
+                      remote, current_branch->name);
+       }
+       exit(1);
+}
+
 int cmd_rebase(int argc, const char **argv, const char *prefix)
 {
        struct rebase_options options = {
                .type = REBASE_UNSPECIFIED,
                .flags = REBASE_NO_QUIET,
-               .git_am_opt = STRBUF_INIT,
+               .git_am_opts = ARGV_ARRAY_INIT,
                .allow_rerere_autoupdate  = -1,
                .allow_empty_message = 1,
+               .git_format_patch_opt = STRBUF_INIT,
        };
        const char *branch_name;
        int ret, flags, total_argc, in_progress = 0;
@@ -643,16 +779,13 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                ACTION_EDIT_TODO,
                ACTION_SHOW_CURRENT_PATCH,
        } action = NO_ACTION;
-       int committer_date_is_author_date = 0;
-       int ignore_date = 0;
-       int ignore_whitespace = 0;
        const char *gpg_sign = NULL;
-       int opt_c = -1;
-       struct string_list whitespace = STRING_LIST_INIT_NODUP;
        struct string_list exec = STRING_LIST_INIT_NODUP;
        const char *rebase_merges = NULL;
        int fork_point = -1;
        struct string_list strategy_options = STRING_LIST_INIT_NODUP;
+       struct object_id squash_onto;
+       char *squash_onto_name = NULL;
        struct option builtin_rebase_options[] = {
                OPT_STRING(0, "onto", &options.onto_name,
                           N_("revision"),
@@ -668,15 +801,20 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
                        N_("do not show diffstat of what changed upstream"),
                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
-               OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
-                        N_("passed to 'git apply'")),
                OPT_BOOL(0, "signoff", &options.signoff,
                         N_("add a Signed-off-by: line to each commit")),
-               OPT_BOOL(0, "committer-date-is-author-date",
-                        &committer_date_is_author_date,
-                        N_("passed to 'git am'")),
-               OPT_BOOL(0, "ignore-date", &ignore_date,
-                        N_("passed to 'git am'")),
+               OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
+                                 NULL, N_("passed to 'git am'"),
+                                 PARSE_OPT_NOARG),
+               OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
+                                 &options.git_am_opts, NULL,
+                                 N_("passed to 'git am'"), PARSE_OPT_NOARG),
+               OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
+                                 N_("passed to 'git am'"), PARSE_OPT_NOARG),
+               OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
+                                 N_("passed to 'git apply'"), 0),
+               OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
+                                 N_("action"), N_("passed to 'git apply'"), 0),
                OPT_BIT('f', "force-rebase", &options.flags,
                        N_("cherry-pick all commits, even if unchanged"),
                        REBASE_FORCE),
@@ -720,10 +858,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                { OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
                        N_("GPG-sign commits"),
                        PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
-               OPT_STRING_LIST(0, "whitespace", &whitespace,
-                               N_("whitespace"), N_("passed to 'git apply'")),
-               OPT_SET_INT('C', NULL, &opt_c, N_("passed to 'git apply'"),
-                           REBASE_AM),
                OPT_BOOL(0, "autostash", &options.autostash,
                         N_("automatically stash/stash pop before and after")),
                OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
@@ -744,8 +878,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                                N_("option"),
                                N_("pass the argument through to the merge "
                                   "strategy")),
+               OPT_BOOL(0, "root", &options.root,
+                        N_("rebase all reachable commits up to the root(s)")),
                OPT_END(),
        };
+       int i;
 
        /*
         * NEEDSWORK: Once the builtin rebase has been tested enough
@@ -862,7 +999,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                rerere_clear(&merge_rr);
                string_list_clear(&merge_rr, 1);
 
-               if (reset_head(NULL, "reset", NULL, 0) < 0)
+               if (reset_head(NULL, "reset", NULL, 0, NULL, NULL) < 0)
                        die(_("could not discard worktree changes"));
                if (read_basic_state(&options))
                        exit(1);
@@ -878,7 +1015,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                if (read_basic_state(&options))
                        exit(1);
                if (reset_head(&options.orig_head, "reset",
-                              options.head_name, 0) < 0)
+                              options.head_name, 0, NULL, NULL) < 0)
                        die(_("could not move back to %s"),
                            oid_to_hex(&options.orig_head));
                ret = finish_rebase(&options);
@@ -926,22 +1063,27 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                    state_dir_base, cmd_live_rebase, buf.buf);
        }
 
-       if (!(options.flags & REBASE_NO_QUIET))
-               strbuf_addstr(&options.git_am_opt, " -q");
-
-       if (committer_date_is_author_date) {
-               strbuf_addstr(&options.git_am_opt,
-                             " --committer-date-is-author-date");
-               options.flags |= REBASE_FORCE;
+       for (i = 0; i < options.git_am_opts.argc; i++) {
+               const char *option = options.git_am_opts.argv[i], *p;
+               if (!strcmp(option, "--committer-date-is-author-date") ||
+                   !strcmp(option, "--ignore-date") ||
+                   !strcmp(option, "--whitespace=fix") ||
+                   !strcmp(option, "--whitespace=strip"))
+                       options.flags |= REBASE_FORCE;
+               else if (skip_prefix(option, "-C", &p)) {
+                       while (*p)
+                               if (!isdigit(*(p++)))
+                                       die(_("switch `C' expects a "
+                                             "numerical value"));
+               } else if (skip_prefix(option, "--whitespace=", &p)) {
+                       if (*p && strcmp(p, "warn") && strcmp(p, "nowarn") &&
+                           strcmp(p, "error") && strcmp(p, "error-all"))
+                               die("Invalid whitespace option: '%s'", p);
+               }
        }
 
-       if (ignore_whitespace)
-               strbuf_addstr(&options.git_am_opt, " --ignore-whitespace");
-
-       if (ignore_date) {
-               strbuf_addstr(&options.git_am_opt, " --ignore-date");
-               options.flags |= REBASE_FORCE;
-       }
+       if (!(options.flags & REBASE_NO_QUIET))
+               argv_array_push(&options.git_am_opts, "-q");
 
        if (options.keep_empty)
                imply_interactive(&options, "--keep-empty");
@@ -951,23 +1093,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
        }
 
-       if (opt_c >= 0)
-               strbuf_addf(&options.git_am_opt, " -C%d", opt_c);
-
-       if (whitespace.nr) {
-               int i;
-
-               for (i = 0; i < whitespace.nr; i++) {
-                       const char *item = whitespace.items[i].string;
-
-                       strbuf_addf(&options.git_am_opt, " --whitespace=%s",
-                                   item);
-
-                       if ((!strcmp(item, "fix")) || (!strcmp(item, "strip")))
-                               options.flags |= REBASE_FORCE;
-               }
-       }
-
        if (exec.nr) {
                int i;
 
@@ -1021,6 +1146,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                }
        }
 
+       if (options.root && !options.onto_name)
+               imply_interactive(&options, "--root without --onto");
+
+       if (isatty(2) && options.flags & REBASE_NO_QUIET)
+               strbuf_addstr(&options.git_format_patch_opt, " --progress");
+
        switch (options.type) {
        case REBASE_MERGE:
        case REBASE_INTERACTIVE:
@@ -1037,18 +1168,62 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                break;
        }
 
+       if (options.git_am_opts.argc) {
+               /* all am options except -q are compatible only with --am */
+               for (i = options.git_am_opts.argc - 1; i >= 0; i--)
+                       if (strcmp(options.git_am_opts.argv[i], "-q"))
+                               break;
+
+               if (is_interactive(&options) && i >= 0)
+                       die(_("error: cannot combine interactive options "
+                             "(--interactive, --exec, --rebase-merges, "
+                             "--preserve-merges, --keep-empty, --root + "
+                             "--onto) with am options (%s)"), buf.buf);
+               if (options.type == REBASE_MERGE && i >= 0)
+                       die(_("error: cannot combine merge options (--merge, "
+                             "--strategy, --strategy-option) with am options "
+                             "(%s)"), buf.buf);
+       }
+
        if (options.signoff) {
                if (options.type == REBASE_PRESERVE_MERGES)
                        die("cannot combine '--signoff' with "
                            "'--preserve-merges'");
-               strbuf_addstr(&options.git_am_opt, " --signoff");
+               argv_array_push(&options.git_am_opts, "--signoff");
                options.flags |= REBASE_FORCE;
        }
 
+       if (options.type == REBASE_PRESERVE_MERGES)
+               /*
+                * Note: incompatibility with --signoff handled in signoff block above
+                * Note: incompatibility with --interactive is just a strong warning;
+                *       git-rebase.txt caveats with "unless you know what you are doing"
+                */
+               if (options.rebase_merges)
+                       die(_("error: cannot combine '--preserve-merges' with "
+                             "'--rebase-merges'"));
+
+       if (options.rebase_merges) {
+               if (strategy_options.nr)
+                       die(_("error: cannot combine '--rebase-merges' with "
+                             "'--strategy-option'"));
+               if (options.strategy)
+                       die(_("error: cannot combine '--rebase-merges' with "
+                             "'--strategy'"));
+       }
+
        if (!options.root) {
-               if (argc < 1)
-                       die("TODO: handle @{upstream}");
-               else {
+               if (argc < 1) {
+                       struct branch *branch;
+
+                       branch = branch_get(NULL);
+                       options.upstream_name = branch_get_upstream(branch,
+                                                                   NULL);
+                       if (!options.upstream_name)
+                               error_on_missing_default_upstream();
+                       if (fork_point < 0)
+                               fork_point = 1;
+               } else {
                        options.upstream_name = argv[0];
                        argc--;
                        argv++;
@@ -1059,8 +1234,22 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                if (!options.upstream)
                        die(_("invalid upstream '%s'"), options.upstream_name);
                options.upstream_arg = options.upstream_name;
-       } else
-               die("TODO: upstream for --root");
+       } else {
+               if (!options.onto_name) {
+                       if (commit_tree("", 0, the_hash_algo->empty_tree, NULL,
+                                       &squash_onto, NULL, NULL) < 0)
+                               die(_("Could not create new root commit"));
+                       options.squash_onto = &squash_onto;
+                       options.onto_name = squash_onto_name =
+                               xstrdup(oid_to_hex(&squash_onto));
+               }
+               options.upstream_name = NULL;
+               options.upstream = NULL;
+               if (argc > 1)
+                       usage_with_options(builtin_rebase_usage,
+                                          builtin_rebase_options);
+               options.upstream_arg = "--root";
+       }
 
        /* Make sure the branch to rebase onto is valid. */
        if (!options.onto_name)
@@ -1144,7 +1333,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                        update_index_if_able(&the_index, &lock_file);
                rollback_lock_file(&lock_file);
 
-               if (has_unstaged_changes(0) || has_uncommitted_changes(0)) {
+               if (has_unstaged_changes(1) || has_uncommitted_changes(1)) {
                        const char *autostash =
                                state_dir_path("autostash", &options);
                        struct child_process stash = CHILD_PROCESS_INIT;
@@ -1170,10 +1359,10 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                        if (safe_create_leading_directories_const(autostash))
                                die(_("Could not create directory for '%s'"),
                                    options.state_dir);
-                       write_file(autostash, "%s", buf.buf);
+                       write_file(autostash, "%s", oid_to_hex(&oid));
                        printf(_("Created autostash: %s\n"), buf.buf);
                        if (reset_head(&head->object.oid, "reset --hard",
-                                      NULL, 0) < 0)
+                                      NULL, 0, NULL, NULL) < 0)
                                die(_("could not reset --hard"));
                        printf(_("HEAD is now at %s"),
                               find_unique_abbrev(&head->object.oid,
@@ -1208,6 +1397,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
         */
        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)) {
                int flag;
 
@@ -1226,7 +1416,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                                strbuf_addf(&buf, "rebase: checkout %s",
                                            options.switch_to);
                                if (reset_head(&oid, "checkout",
-                                              options.head_name, 0) < 0) {
+                                              options.head_name, 0,
+                                              NULL, NULL) < 0) {
                                        ret = !!error(_("could not switch to "
                                                        "%s"),
                                                      options.switch_to);
@@ -1291,10 +1482,29 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                         "it...\n"));
 
        strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
-       if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
+       if (reset_head(&options.onto->object.oid, "checkout", NULL, 1,
+           NULL, msg.buf))
                die(_("Could not detach HEAD"));
        strbuf_release(&msg);
 
+       /*
+        * If the onto is a proper descendant of the tip of the branch, then
+        * we just fast-forwarded.
+        */
+       strbuf_reset(&msg);
+       if (!oidcmp(&merge_base, &options.orig_head)) {
+               printf(_("Fast-forwarded %s to %s. \n"),
+                       branch_name, options.onto_name);
+               strbuf_addf(&msg, "rebase finished: %s onto %s",
+                       options.head_name ? options.head_name : "detached HEAD",
+                       oid_to_hex(&options.onto->object.oid));
+               reset_head(NULL, "Fast-forwarded", options.head_name, 0,
+                          "HEAD", msg.buf);
+               strbuf_release(&msg);
+               ret = !!finish_rebase(&options);
+               goto cleanup;
+       }
+
        strbuf_addf(&revisions, "%s..%s",
                    options.root ? oid_to_hex(&options.onto->object.oid) :
                    (options.restrict_revision ?
@@ -1312,5 +1522,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
        free(options.head_name);
        free(options.gpg_sign_opt);
        free(options.cmd);
+       free(squash_onto_name);
        return ret;
 }