merge: remove drop_save() in favor of remove_merge_branch_state()
[gitweb.git] / builtin / rebase.c
index 0ee06aa3631ee89761d570b433994cc77302742e..7c7bc13e912aa8ba5d2c4dfa781fb74cd20ac6d4 100644 (file)
@@ -4,6 +4,7 @@
  * Copyright (c) 2018 Pratik Karki
  */
 
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "run-command.h"
 #include "exec-cmd.h"
@@ -23,6 +24,7 @@
 #include "revision.h"
 #include "commit-reach.h"
 #include "rerere.h"
+#include "branch.h"
 
 static char const * const builtin_rebase_usage[] = {
        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
@@ -48,7 +50,10 @@ static int use_builtin_rebase(void)
 {
        struct child_process cp = CHILD_PROCESS_INIT;
        struct strbuf out = STRBUF_INIT;
-       int ret;
+       int ret, env = git_env_bool("GIT_TEST_REBASE_USE_BUILTIN", -1);
+
+       if (env != -1)
+               return env;
 
        argv_array_pushl(&cp.args,
                         "config", "--bool", "rebase.usebuiltin", NULL);
@@ -87,7 +92,7 @@ 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;
@@ -100,6 +105,7 @@ struct rebase_options {
        int rebase_merges, rebase_cousins;
        char *strategy, *strategy_opts;
        struct strbuf git_format_patch_opt;
+       int reschedule_failed_exec;
 };
 
 static int is_interactive(struct rebase_options *opts)
@@ -118,7 +124,7 @@ static void imply_interactive(struct rebase_options *opts, const char *option)
        case REBASE_PRESERVE_MERGES:
                break;
        case REBASE_MERGE:
-               /* we silently *upgrade* --merge to --interactive if needed */
+               /* we now implement --merge via --interactive */
        default:
                opts->type = REBASE_INTERACTIVE; /* implied */
                break;
@@ -181,10 +187,7 @@ static int read_basic_state(struct rebase_options *opts)
        if (get_oid(buf.buf, &opts->orig_head))
                return error(_("invalid orig-head: '%s'"), buf.buf);
 
-       strbuf_reset(&buf);
-       if (read_one(state_dir_path("quiet", opts), &buf))
-               return -1;
-       if (buf.len)
+       if (file_exists(state_dir_path("quiet", opts)))
                opts->flags &= ~REBASE_NO_QUIET;
        else
                opts->flags |= REBASE_NO_QUIET;
@@ -242,6 +245,37 @@ static int read_basic_state(struct rebase_options *opts)
        return 0;
 }
 
+static int write_basic_state(struct rebase_options *opts)
+{
+       write_file(state_dir_path("head-name", opts), "%s",
+                  opts->head_name ? opts->head_name : "detached HEAD");
+       write_file(state_dir_path("onto", opts), "%s",
+                  opts->onto ? oid_to_hex(&opts->onto->object.oid) : "");
+       write_file(state_dir_path("orig-head", opts), "%s",
+                  oid_to_hex(&opts->orig_head));
+       write_file(state_dir_path("quiet", opts), "%s",
+                  opts->flags & REBASE_NO_QUIET ? "" : "t");
+       if (opts->flags & REBASE_VERBOSE)
+               write_file(state_dir_path("verbose", opts), "%s", "");
+       if (opts->strategy)
+               write_file(state_dir_path("strategy", opts), "%s",
+                          opts->strategy);
+       if (opts->strategy_opts)
+               write_file(state_dir_path("strategy_opts", opts), "%s",
+                          opts->strategy_opts);
+       if (opts->allow_rerere_autoupdate >= 0)
+               write_file(state_dir_path("allow_rerere_autoupdate", opts),
+                          "-%s-rerere-autoupdate",
+                          opts->allow_rerere_autoupdate ? "" : "-no");
+       if (opts->gpg_sign_opt)
+               write_file(state_dir_path("gpg_sign_opt", opts), "%s",
+                          opts->gpg_sign_opt);
+       if (opts->signoff)
+               write_file(state_dir_path("strategy", opts), "--signoff");
+
+       return 0;
+}
+
 static int apply_autostash(struct rebase_options *opts)
 {
        const char *path = state_dir_path("autostash", opts);
@@ -329,6 +363,161 @@ static void add_var(struct strbuf *buf, const char *name, const char *value)
        }
 }
 
+#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
+
+#define RESET_HEAD_DETACH (1<<0)
+#define RESET_HEAD_HARD (1<<1)
+#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
+#define RESET_HEAD_REFS_ONLY (1<<3)
+
+static int reset_head(struct object_id *oid, const char *action,
+                     const char *switch_to_branch, unsigned flags,
+                     const char *reflog_orig_head, const char *reflog_head)
+{
+       unsigned detach_head = flags & RESET_HEAD_DETACH;
+       unsigned reset_hard = flags & RESET_HEAD_HARD;
+       unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+       unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
+       struct object_id head_oid;
+       struct tree_desc desc[2] = { { NULL }, { NULL } };
+       struct lock_file lock = LOCK_INIT;
+       struct unpack_trees_options unpack_tree_opts;
+       struct tree *tree;
+       const char *reflog_action;
+       struct strbuf msg = STRBUF_INIT;
+       size_t prefix_len;
+       struct object_id *orig = NULL, oid_orig,
+               *old_orig = NULL, oid_old_orig;
+       int ret = 0, nr = 0;
+
+       if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
+               BUG("Not a fully qualified branch: '%s'", switch_to_branch);
+
+       if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
+               ret = -1;
+               goto leave_reset_head;
+       }
+
+       if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
+               ret = error(_("could not determine HEAD revision"));
+               goto leave_reset_head;
+       }
+
+       if (!oid)
+               oid = &head_oid;
+
+       if (refs_only)
+               goto reset_head_refs;
+
+       memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
+       setup_unpack_trees_porcelain(&unpack_tree_opts, action);
+       unpack_tree_opts.head_idx = 1;
+       unpack_tree_opts.src_index = the_repository->index;
+       unpack_tree_opts.dst_index = the_repository->index;
+       unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
+       unpack_tree_opts.update = 1;
+       unpack_tree_opts.merge = 1;
+       if (!detach_head)
+               unpack_tree_opts.reset = 1;
+
+       if (repo_read_index_unmerged(the_repository) < 0) {
+               ret = error(_("could not read index"));
+               goto leave_reset_head;
+       }
+
+       if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
+               ret = error(_("failed to find tree of %s"),
+                           oid_to_hex(&head_oid));
+               goto leave_reset_head;
+       }
+
+       if (!fill_tree_descriptor(&desc[nr++], oid)) {
+               ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
+               goto leave_reset_head;
+       }
+
+       if (unpack_trees(nr, desc, &unpack_tree_opts)) {
+               ret = -1;
+               goto leave_reset_head;
+       }
+
+       tree = parse_tree_indirect(oid);
+       prime_cache_tree(the_repository, the_repository->index, tree);
+
+       if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
+               ret = error(_("could not write index"));
+               goto leave_reset_head;
+       }
+
+reset_head_refs:
+       reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
+       strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
+       prefix_len = msg.len;
+
+       if (!get_oid("ORIG_HEAD", &oid_old_orig))
+               old_orig = &oid_old_orig;
+       if (!get_oid("HEAD", &oid_orig)) {
+               orig = &oid_orig;
+               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);
+       if (!reflog_head) {
+               strbuf_setlen(&msg, prefix_len);
+               strbuf_addstr(&msg, "updating HEAD");
+               reflog_head = msg.buf;
+       }
+       if (!switch_to_branch)
+               ret = update_ref(reflog_head, "HEAD", oid, orig,
+                                detach_head ? REF_NO_DEREF : 0,
+                                UPDATE_REFS_MSG_ON_ERR);
+       else {
+               ret = update_ref(reflog_orig_head, switch_to_branch, oid,
+                                NULL, 0, UPDATE_REFS_MSG_ON_ERR);
+               if (!ret)
+                       ret = create_symref("HEAD", switch_to_branch,
+                                           reflog_head);
+       }
+       if (run_hook)
+               run_hook_le(NULL, "post-checkout",
+                           oid_to_hex(orig ? orig : &null_oid),
+                           oid_to_hex(oid), "1", NULL);
+
+leave_reset_head:
+       strbuf_release(&msg);
+       rollback_lock_file(&lock);
+       while (nr)
+               free((void *)desc[--nr].buffer);
+       return ret;
+}
+
+static int move_to_original_branch(struct rebase_options *opts)
+{
+       struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
+       int ret;
+
+       if (!opts->head_name)
+               return 0; /* nothing to move back to */
+
+       if (!opts->onto)
+               BUG("move_to_original_branch without onto");
+
+       strbuf_addf(&orig_head_reflog, "rebase finished: %s onto %s",
+                   opts->head_name, oid_to_hex(&opts->onto->object.oid));
+       strbuf_addf(&head_reflog, "rebase finished: returning to %s",
+                   opts->head_name);
+       ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
+                        orig_head_reflog.buf, head_reflog.buf);
+
+       strbuf_release(&orig_head_reflog);
+       strbuf_release(&head_reflog);
+       return ret;
+}
+
 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"
@@ -336,10 +525,130 @@ N_("Resolve all conflicts manually, mark them as resolved with\n"
 "To abort and get back to the state before \"git rebase\", run "
 "\"git rebase --abort\".");
 
+static int run_am(struct rebase_options *opts)
+{
+       struct child_process am = CHILD_PROCESS_INIT;
+       struct child_process format_patch = CHILD_PROCESS_INIT;
+       struct strbuf revisions = STRBUF_INIT;
+       int status;
+       char *rebased_patches;
+
+       am.git_cmd = 1;
+       argv_array_push(&am.args, "am");
+
+       if (opts->action && !strcmp("continue", opts->action)) {
+               argv_array_push(&am.args, "--resolved");
+               argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+               if (opts->gpg_sign_opt)
+                       argv_array_push(&am.args, opts->gpg_sign_opt);
+               status = run_command(&am);
+               if (status)
+                       return status;
+
+               return move_to_original_branch(opts);
+       }
+       if (opts->action && !strcmp("skip", opts->action)) {
+               argv_array_push(&am.args, "--skip");
+               argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+               status = run_command(&am);
+               if (status)
+                       return status;
+
+               return move_to_original_branch(opts);
+       }
+       if (opts->action && !strcmp("show-current-patch", opts->action)) {
+               argv_array_push(&am.args, "--show-current-patch");
+               return run_command(&am);
+       }
+
+       strbuf_addf(&revisions, "%s...%s",
+                   oid_to_hex(opts->root ?
+                              /* this is now equivalent to !opts->upstream */
+                              &opts->onto->object.oid :
+                              &opts->upstream->object.oid),
+                   oid_to_hex(&opts->orig_head));
+
+       rebased_patches = xstrdup(git_path("rebased-patches"));
+       format_patch.out = open(rebased_patches,
+                               O_WRONLY | O_CREAT | O_TRUNC, 0666);
+       if (format_patch.out < 0) {
+               status = error_errno(_("could not open '%s' for writing"),
+                                    rebased_patches);
+               free(rebased_patches);
+               argv_array_clear(&am.args);
+               return status;
+       }
+
+       format_patch.git_cmd = 1;
+       argv_array_pushl(&format_patch.args, "format-patch", "-k", "--stdout",
+                        "--full-index", "--cherry-pick", "--right-only",
+                        "--src-prefix=a/", "--dst-prefix=b/", "--no-renames",
+                        "--no-cover-letter", "--pretty=mboxrd", "--topo-order", NULL);
+       if (opts->git_format_patch_opt.len)
+               argv_array_split(&format_patch.args,
+                                opts->git_format_patch_opt.buf);
+       argv_array_push(&format_patch.args, revisions.buf);
+       if (opts->restrict_revision)
+               argv_array_pushf(&format_patch.args, "^%s",
+                                oid_to_hex(&opts->restrict_revision->object.oid));
+
+       status = run_command(&format_patch);
+       if (status) {
+               unlink(rebased_patches);
+               free(rebased_patches);
+               argv_array_clear(&am.args);
+
+               reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
+                          "HEAD", NULL);
+               error(_("\ngit encountered an error while preparing the "
+                       "patches to replay\n"
+                       "these revisions:\n"
+                       "\n    %s\n\n"
+                       "As a result, git cannot rebase them."),
+                     opts->revisions);
+
+               strbuf_release(&revisions);
+               return status;
+       }
+       strbuf_release(&revisions);
+
+       am.in = open(rebased_patches, O_RDONLY);
+       if (am.in < 0) {
+               status = error_errno(_("could not open '%s' for reading"),
+                                    rebased_patches);
+               free(rebased_patches);
+               argv_array_clear(&am.args);
+               return status;
+       }
+
+       argv_array_pushv(&am.args, opts->git_am_opts.argv);
+       argv_array_push(&am.args, "--rebasing");
+       argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
+       argv_array_push(&am.args, "--patch-format=mboxrd");
+       if (opts->allow_rerere_autoupdate > 0)
+               argv_array_push(&am.args, "--rerere-autoupdate");
+       else if (opts->allow_rerere_autoupdate == 0)
+               argv_array_push(&am.args, "--no-rerere-autoupdate");
+       if (opts->gpg_sign_opt)
+               argv_array_push(&am.args, opts->gpg_sign_opt);
+       status = run_command(&am);
+       unlink(rebased_patches);
+       free(rebased_patches);
+
+       if (!status) {
+               return move_to_original_branch(opts);
+       }
+
+       if (is_directory(opts->state_dir))
+               write_basic_state(opts);
+
+       return status;
+}
+
 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;
 
@@ -350,7 +659,8 @@ static int run_specific_rebase(struct rebase_options *opts)
                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=:");
+                       argv_array_push(&child.env_array,
+                                       "GIT_SEQUENCE_EDITOR=:");
                        opts->autosquash = 0;
                }
 
@@ -411,11 +721,18 @@ static int run_specific_rebase(struct rebase_options *opts)
                        argv_array_push(&child.args, opts->gpg_sign_opt);
                if (opts->signoff)
                        argv_array_push(&child.args, "--signoff");
+               if (opts->reschedule_failed_exec)
+                       argv_array_push(&child.args, "--reschedule-failed-exec");
 
                status = run_command(&child);
                goto finished_rebase;
        }
 
+       if (opts->type == REBASE_AM) {
+               status = run_am(opts);
+               goto finished_rebase;
+       }
+
        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
        add_var(&script_snippet, "state_dir", opts->state_dir);
 
@@ -433,7 +750,9 @@ 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",
@@ -469,7 +788,7 @@ static int run_specific_rebase(struct rebase_options *opts)
        if (is_interactive(opts) &&
            !(opts->flags & REBASE_INTERACTIVE_EXPLICIT)) {
                strbuf_addstr(&script_snippet,
-                             "GIT_EDITOR=:; export GIT_EDITOR; ");
+                             "GIT_SEQUENCE_EDITOR=:; export GIT_SEQUENCE_EDITOR; ");
                opts->autosquash = 0;
        }
 
@@ -478,10 +797,6 @@ static int run_specific_rebase(struct rebase_options *opts)
                backend = "git-rebase--am";
                backend_func = "git_rebase__am";
                break;
-       case REBASE_MERGE:
-               backend = "git-rebase--merge";
-               backend_func = "git_rebase__merge";
-               break;
        case REBASE_PRESERVE_MERGES:
                backend = "git-rebase--preserve-merges";
                backend_func = "git_rebase__preserve_merges";
@@ -520,112 +835,6 @@ static int run_specific_rebase(struct rebase_options *opts)
        return status ? -1 : 0;
 }
 
-#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 *reflog_orig_head, const char *reflog_head)
-{
-       struct object_id head_oid;
-       struct tree_desc desc;
-       struct lock_file lock = LOCK_INIT;
-       struct unpack_trees_options unpack_tree_opts;
-       struct tree *tree;
-       const char *reflog_action;
-       struct strbuf msg = STRBUF_INIT;
-       size_t prefix_len;
-       struct object_id *orig = NULL, oid_orig,
-               *old_orig = NULL, oid_old_orig;
-       int ret = 0;
-
-       if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
-               BUG("Not a fully qualified branch: '%s'", switch_to_branch);
-
-       if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
-               return -1;
-
-       if (!oid) {
-               if (get_oid("HEAD", &head_oid)) {
-                       rollback_lock_file(&lock);
-                       return error(_("could not determine HEAD revision"));
-               }
-               oid = &head_oid;
-       }
-
-       memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
-       setup_unpack_trees_porcelain(&unpack_tree_opts, action);
-       unpack_tree_opts.head_idx = 1;
-       unpack_tree_opts.src_index = the_repository->index;
-       unpack_tree_opts.dst_index = the_repository->index;
-       unpack_tree_opts.fn = oneway_merge;
-       unpack_tree_opts.update = 1;
-       unpack_tree_opts.merge = 1;
-       if (!detach_head)
-               unpack_tree_opts.reset = 1;
-
-       if (read_index_unmerged(the_repository->index) < 0) {
-               rollback_lock_file(&lock);
-               return error(_("could not read index"));
-       }
-
-       if (!fill_tree_descriptor(&desc, oid)) {
-               error(_("failed to find tree of %s"), oid_to_hex(oid));
-               rollback_lock_file(&lock);
-               free((void *)desc.buffer);
-               return -1;
-       }
-
-       if (unpack_trees(1, &desc, &unpack_tree_opts)) {
-               rollback_lock_file(&lock);
-               free((void *)desc.buffer);
-               return -1;
-       }
-
-       tree = parse_tree_indirect(oid);
-       prime_cache_tree(the_repository->index, tree);
-
-       if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
-               ret = error(_("could not write index"));
-       free((void *)desc.buffer);
-
-       if (ret)
-               return ret;
-
-       reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
-       strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
-       prefix_len = msg.len;
-
-       if (!get_oid("ORIG_HEAD", &oid_old_orig))
-               old_orig = &oid_old_orig;
-       if (!get_oid("HEAD", &oid_orig)) {
-               orig = &oid_orig;
-               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);
-       if (!reflog_head) {
-               strbuf_setlen(&msg, prefix_len);
-               strbuf_addstr(&msg, "updating HEAD");
-               reflog_head = msg.buf;
-       }
-       if (!switch_to_branch)
-               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(reflog_head, "HEAD", oid, NULL, 0,
-                                        UPDATE_REFS_MSG_ON_ERR);
-       }
-
-       strbuf_release(&msg);
-       return ret;
-}
-
 static int rebase_config(const char *var, const char *value, void *data)
 {
        struct rebase_options *opts = data;
@@ -655,6 +864,11 @@ static int rebase_config(const char *var, const char *value, void *data)
                return 0;
        }
 
+       if (!strcmp(var, "rebase.reschedulefailedexec")) {
+               opts->reschedule_failed_exec = git_config_bool(var, value);
+               return 0;
+       }
+
        return git_default_config(var, value, data);
 }
 
@@ -703,6 +917,9 @@ static int parse_opt_merge(const struct option *opt, const char *arg, int unset)
 {
        struct rebase_options *opts = opt->value;
 
+       BUG_ON_OPT_NEG(unset);
+       BUG_ON_OPT_ARG(arg);
+
        if (!is_interactive(opts))
                opts->type = REBASE_MERGE;
 
@@ -715,6 +932,9 @@ static int parse_opt_interactive(const struct option *opt, const char *arg,
 {
        struct rebase_options *opts = opt->value;
 
+       BUG_ON_OPT_NEG(unset);
+       BUG_ON_OPT_ARG(arg);
+
        opts->type = REBASE_INTERACTIVE;
        opts->flags |= REBASE_INTERACTIVE_EXPLICIT;
 
@@ -751,12 +971,42 @@ static void NORETURN error_on_missing_default_upstream(void)
        exit(1);
 }
 
+static void set_reflog_action(struct rebase_options *options)
+{
+       const char *env;
+       struct strbuf buf = STRBUF_INIT;
+
+       if (!is_interactive(options))
+               return;
+
+       env = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
+       if (env && strcmp("rebase", env))
+               return; /* only override it if it is "rebase" */
+
+       strbuf_addf(&buf, "rebase -i (%s)", options->action);
+       setenv(GIT_REFLOG_ACTION_ENVIRONMENT, buf.buf, 1);
+       strbuf_release(&buf);
+}
+
+static int check_exec_cmd(const char *cmd)
+{
+       if (strchr(cmd, '\n'))
+               return error(_("exec commands cannot contain newlines"));
+
+       /* Does the command consist purely of whitespace? */
+       if (!cmd[strspn(cmd, " \t\r\f\v")])
+               return error(_("empty exec command"));
+
+       return 0;
+}
+
+
 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,
@@ -777,12 +1027,7 @@ 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;
@@ -804,15 +1049,20 @@ 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),
@@ -846,7 +1096,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                               "them"), REBASE_PRESERVE_MERGES),
                OPT_BOOL(0, "rerere-autoupdate",
                         &options.allow_rerere_autoupdate,
-                        N_("allow rerere to update index  with resolved "
+                        N_("allow rerere to update index with resolved "
                            "conflict")),
                OPT_BOOL('k', "keep-empty", &options.keep_empty,
                         N_("preserve empty commits during rebase")),
@@ -856,10 +1106,6 @@ 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"),
@@ -882,8 +1128,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                                   "strategy")),
                OPT_BOOL(0, "root", &options.root,
                         N_("rebase all reachable commits up to the root(s)")),
+               OPT_BOOL(0, "reschedule-failed-exec",
+                        &options.reschedule_failed_exec,
+                        N_("automatically re-schedule any `exec` that fails")),
                OPT_END(),
        };
+       int i;
 
        /*
         * NEEDSWORK: Once the builtin rebase has been tested enough
@@ -956,6 +1206,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
        if (action != NO_ACTION && !in_progress)
                die(_("No rebase in progress?"));
+       setenv(GIT_REFLOG_ACTION_ENVIRONMENT, "rebase", 0);
 
        if (action == ACTION_EDIT_TODO && !is_interactive(&options))
                die(_("The --edit-todo action can only be used during "
@@ -968,22 +1219,22 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                int fd;
 
                options.action = "continue";
+               set_reflog_action(&options);
 
                /* Sanity check */
                if (get_oid("HEAD", &head))
                        die(_("Cannot read HEAD"));
 
                fd = hold_locked_index(&lock_file, 0);
-               if (read_index(the_repository->index) < 0)
+               if (repo_read_index(the_repository) < 0)
                        die(_("could not read index"));
                refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL,
                              NULL);
                if (0 <= fd)
-                       update_index_if_able(the_repository->index,
-                                            &lock_file);
+                       repo_update_index_if_able(the_repository, &lock_file);
                rollback_lock_file(&lock_file);
 
-               if (has_unstaged_changes(1)) {
+               if (has_unstaged_changes(the_repository, 1)) {
                        puts(_("You must edit all merge conflicts and then\n"
                               "mark them as resolved using git add"));
                        exit(1);
@@ -996,12 +1247,15 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                struct string_list merge_rr = STRING_LIST_INIT_DUP;
 
                options.action = "skip";
+               set_reflog_action(&options);
 
-               rerere_clear(&merge_rr);
+               rerere_clear(the_repository, &merge_rr);
                string_list_clear(&merge_rr, 1);
 
-               if (reset_head(NULL, "reset", NULL, 0, NULL, NULL) < 0)
+               if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
+                              NULL, NULL) < 0)
                        die(_("could not discard worktree changes"));
+               remove_branch_state(the_repository);
                if (read_basic_state(&options))
                        exit(1);
                goto run_rebase;
@@ -1009,16 +1263,19 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
        case ACTION_ABORT: {
                struct string_list merge_rr = STRING_LIST_INIT_DUP;
                options.action = "abort";
+               set_reflog_action(&options);
 
-               rerere_clear(&merge_rr);
+               rerere_clear(the_repository, &merge_rr);
                string_list_clear(&merge_rr, 1);
 
                if (read_basic_state(&options))
                        exit(1);
                if (reset_head(&options.orig_head, "reset",
-                              options.head_name, 0, NULL, NULL) < 0)
+                              options.head_name, RESET_HEAD_HARD,
+                              NULL, NULL) < 0)
                        die(_("could not move back to %s"),
                            oid_to_hex(&options.orig_head));
+               remove_branch_state(the_repository);
                ret = finish_rebase(&options);
                goto cleanup;
        }
@@ -1064,22 +1321,31 @@ 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");
+       for (i = 0; i < exec.nr; i++)
+               if (check_exec_cmd(exec.items[i].string))
+                       exit(1);
 
-       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");
@@ -1089,23 +1355,6 @@ 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;
 
@@ -1159,6 +1408,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                }
        }
 
+       if (options.type == REBASE_MERGE)
+               imply_interactive(&options, "--merge");
+
        if (options.root && !options.onto_name)
                imply_interactive(&options, "--root without --onto");
 
@@ -1181,52 +1433,49 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                break;
        }
 
-       if (options.git_am_opt.len) {
-               const char *p;
+       if (options.reschedule_failed_exec && !is_interactive(&options))
+               die(_("%s requires an interactive rebase"), "--reschedule-failed-exec");
 
+       if (options.git_am_opts.argc) {
                /* all am options except -q are compatible only with --am */
-               strbuf_reset(&buf);
-               strbuf_addbuf(&buf, &options.git_am_opt);
-               strbuf_addch(&buf, ' ');
-               while ((p = strstr(buf.buf, " -q ")))
-                       strbuf_splice(&buf, p - buf.buf, 4, " ", 1);
-               strbuf_trim(&buf);
-
-               if (is_interactive(&options) && buf.len)
-                       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 && buf.len)
-                       die(_("error: cannot combine merge options (--merge, "
-                             "--strategy, --strategy-option) with am options "
-                             "(%s)"), buf.buf);
+               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(_("cannot combine am options with either "
+                             "interactive or merge options"));
        }
 
        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)
+       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 "
+                       die(_("cannot combine '--preserve-merges' with "
                              "'--rebase-merges'"));
 
+               if (options.reschedule_failed_exec)
+                       die(_("error: cannot combine '--preserve-merges' with "
+                             "'--reschedule-failed-exec'"));
+       }
+
        if (options.rebase_merges) {
                if (strategy_options.nr)
-                       die(_("error: cannot combine '--rebase-merges' with "
+                       die(_("cannot combine '--rebase-merges' with "
                              "'--strategy-option'"));
                if (options.strategy)
-                       die(_("error: cannot combine '--rebase-merges' with "
+                       die(_("cannot combine '--rebase-merges' with "
                              "'--strategy'"));
        }
 
@@ -1338,7 +1587,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                        get_fork_point(options.upstream_name, head);
        }
 
-       if (read_index(the_repository->index) < 0)
+       if (repo_read_index(the_repository) < 0)
                die(_("could not read index"));
 
        if (options.autostash) {
@@ -1348,10 +1597,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                fd = hold_locked_index(&lock_file, 0);
                refresh_cache(REFRESH_QUIET);
                if (0 <= fd)
-                       update_index_if_able(&the_index, &lock_file);
+                       repo_update_index_if_able(the_repository, &lock_file);
                rollback_lock_file(&lock_file);
 
-               if (has_unstaged_changes(1) || has_uncommitted_changes(1)) {
+               if (has_unstaged_changes(the_repository, 1) ||
+                   has_uncommitted_changes(the_repository, 1)) {
                        const char *autostash =
                                state_dir_path("autostash", &options);
                        struct child_process stash = CHILD_PROCESS_INIT;
@@ -1380,7 +1630,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                        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, NULL, NULL) < 0)
+                                      NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
                                die(_("could not reset --hard"));
                        printf(_("HEAD is now at %s"),
                               find_unique_abbrev(&head->object.oid,
@@ -1392,12 +1642,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                        putchar('\n');
 
                        if (discard_index(the_repository->index) < 0 ||
-                               read_index(the_repository->index) < 0)
+                               repo_read_index(the_repository) < 0)
                                die(_("could not read index"));
                }
        }
 
-       if (require_clean_work_tree("rebase",
+       if (require_clean_work_tree(the_repository, "rebase",
                                    _("Please commit or stash them."), 1, 1)) {
                ret = 1;
                goto cleanup;
@@ -1431,11 +1681,13 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                                }
 
                                strbuf_reset(&buf);
-                               strbuf_addf(&buf, "rebase: checkout %s",
+                               strbuf_addf(&buf, "%s: checkout %s",
+                                           getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
                                            options.switch_to);
                                if (reset_head(&oid, "checkout",
-                                              options.head_name, 0,
-                                              NULL, NULL) < 0) {
+                                              options.head_name,
+                                              RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
+                                              NULL, buf.buf) < 0) {
                                        ret = !!error(_("could not switch to "
                                                        "%s"),
                                                      options.switch_to);
@@ -1472,10 +1724,15 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
        if (options.flags & REBASE_DIFFSTAT) {
                struct diff_options opts;
 
-               if (options.flags & REBASE_VERBOSE)
-                       printf(_("Changes from %s to %s:\n"),
-                               oid_to_hex(&merge_base),
-                               oid_to_hex(&options.onto->object.oid));
+               if (options.flags & REBASE_VERBOSE) {
+                       if (is_null_oid(&merge_base))
+                               printf(_("Changes to %s:\n"),
+                                      oid_to_hex(&options.onto->object.oid));
+                       else
+                               printf(_("Changes from %s to %s:\n"),
+                                      oid_to_hex(&merge_base),
+                                      oid_to_hex(&options.onto->object.oid));
+               }
 
                /* We want color (if set), but no pager */
                diff_setup(&opts);
@@ -1485,8 +1742,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
                opts.detect_rename = DIFF_DETECT_RENAME;
                diff_setup_done(&opts);
-               diff_tree_oid(&merge_base, &options.onto->object.oid,
-                             "", &opts);
+               diff_tree_oid(is_null_oid(&merge_base) ?
+                             the_hash_algo->empty_tree : &merge_base,
+                             &options.onto->object.oid, "", &opts);
                diffcore_std(&opts);
                diff_flush(&opts);
        }
@@ -1499,9 +1757,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                printf(_("First, rewinding head to replay your work on top of "
                         "it...\n"));
 
-       strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
-       if (reset_head(&options.onto->object.oid, "checkout", NULL, 1,
-           NULL, msg.buf))
+       strbuf_addf(&msg, "%s: checkout %s",
+                   getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
+       if (reset_head(&options.onto->object.oid, "checkout", NULL,
+                      RESET_HEAD_DETACH | RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
+                      NULL, msg.buf))
                die(_("Could not detach HEAD"));
        strbuf_release(&msg);
 
@@ -1511,7 +1771,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
         */
        strbuf_reset(&msg);
        if (!oidcmp(&merge_base, &options.orig_head)) {
-               printf(_("Fast-forwarded %s to %s. \n"),
+               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",