completion: correct zsh detection when run from git-completion.zsh
[gitweb.git] / builtin / am.c
index 31fb60578f6caacfb376fe84938dda9432dcfc5a..1151b5c73aec81dbfca36a799cd4049429c75973 100644 (file)
@@ -4,6 +4,7 @@
  * Based on git-am.sh by Junio C Hamano.
  */
 #include "cache.h"
+#include "config.h"
 #include "builtin.h"
 #include "exec_cmd.h"
 #include "parse-options.h"
@@ -30,6 +31,7 @@
 #include "mailinfo.h"
 #include "apply.h"
 #include "string-list.h"
+#include "packfile.h"
 
 /**
  * Returns 1 if the file is empty or does not exist, 0 otherwise.
@@ -134,17 +136,15 @@ struct am_state {
 };
 
 /**
- * Initializes am_state with the default values. The state directory is set to
- * dir.
+ * Initializes am_state with the default values.
  */
-static void am_state_init(struct am_state *state, const char *dir)
+static void am_state_init(struct am_state *state)
 {
        int gpgsign;
 
        memset(state, 0, sizeof(*state));
 
-       assert(dir);
-       state->dir = xstrdup(dir);
+       state->dir = git_pathdup("rebase-apply");
 
        state->prec = 4;
 
@@ -432,6 +432,14 @@ static void am_load(struct am_state *state)
        read_state_file(&sb, state, "utf8", 1);
        state->utf8 = !strcmp(sb.buf, "t");
 
+       if (file_exists(am_path(state, "rerere-autoupdate"))) {
+               read_state_file(&sb, state, "rerere-autoupdate", 1);
+               state->allow_rerere_autoupdate = strcmp(sb.buf, "t") ?
+                       RERERE_NOAUTOUPDATE : RERERE_AUTOUPDATE;
+       } else {
+               state->allow_rerere_autoupdate = 0;
+       }
+
        read_state_file(&sb, state, "keep", 1);
        if (!strcmp(sb.buf, "t"))
                state->keep = KEEP_TRUE;
@@ -485,8 +493,7 @@ static int run_applypatch_msg_hook(struct am_state *state)
        ret = run_hook_le(NULL, "applypatch-msg", am_path(state, "final-commit"), NULL);
 
        if (!ret) {
-               free(state->msg);
-               state->msg = NULL;
+               FREE_AND_NULL(state->msg);
                if (read_commit_msg(state) < 0)
                        die(_("'%s' was deleted by the applypatch-msg hook"),
                                am_path(state, "final-commit"));
@@ -565,7 +572,7 @@ static int copy_notes_for_rebase(const struct am_state *state)
                        goto finish;
                }
 
-               if (copy_note_for_rewrite(c, from_obj.hash, to_obj.hash))
+               if (copy_note_for_rewrite(c, &from_obj, &to_obj))
                        ret = error(_("Failed to copy notes from '%s' to '%s'"),
                                        oid_to_hex(&from_obj), oid_to_hex(&to_obj));
        }
@@ -664,9 +671,7 @@ static int detect_patch_format(const char **paths)
                goto done;
        }
 
-       strbuf_reset(&l2);
        strbuf_getline(&l2, fp);
-       strbuf_reset(&l3);
        strbuf_getline(&l3, fp);
 
        /*
@@ -689,6 +694,8 @@ static int detect_patch_format(const char **paths)
 done:
        fclose(fp);
        strbuf_release(&l1);
+       strbuf_release(&l2);
+       strbuf_release(&l3);
        return ret;
 }
 
@@ -701,6 +708,7 @@ static int split_mail_mbox(struct am_state *state, const char **paths,
 {
        struct child_process cp = CHILD_PROCESS_INIT;
        struct strbuf last = STRBUF_INIT;
+       int ret;
 
        cp.git_cmd = 1;
        argv_array_push(&cp.args, "mailsplit");
@@ -714,13 +722,16 @@ static int split_mail_mbox(struct am_state *state, const char **paths,
        argv_array_push(&cp.args, "--");
        argv_array_pushv(&cp.args, paths);
 
-       if (capture_command(&cp, &last, 8))
-               return -1;
+       ret = capture_command(&cp, &last, 8);
+       if (ret)
+               goto exit;
 
        state->cur = 1;
        state->last = strtol(last.buf, NULL, 10);
 
-       return 0;
+exit:
+       strbuf_release(&last);
+       return ret ? -1 : 0;
 }
 
 /**
@@ -762,14 +773,18 @@ static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
                mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);
 
                out = fopen(mail, "w");
-               if (!out)
+               if (!out) {
+                       if (in != stdin)
+                               fclose(in);
                        return error_errno(_("could not open '%s' for writing"),
                                           mail);
+               }
 
                ret = fn(out, in, keep_cr);
 
                fclose(out);
-               fclose(in);
+               if (in != stdin)
+                       fclose(in);
 
                if (ret)
                        return error(_("could not parse patch '%s'"), *paths);
@@ -870,6 +885,7 @@ static int split_mail_stgit_series(struct am_state *state, const char **paths,
 static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
 {
        struct strbuf sb = STRBUF_INIT;
+       int rc = 0;
 
        while (!strbuf_getline_lf(&sb, in)) {
                const char *str;
@@ -877,25 +893,33 @@ static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
                if (skip_prefix(sb.buf, "# User ", &str))
                        fprintf(out, "From: %s\n", str);
                else if (skip_prefix(sb.buf, "# Date ", &str)) {
-                       unsigned long timestamp;
+                       timestamp_t timestamp;
                        long tz, tz2;
                        char *end;
 
                        errno = 0;
-                       timestamp = strtoul(str, &end, 10);
-                       if (errno)
-                               return error(_("invalid timestamp"));
+                       timestamp = parse_timestamp(str, &end, 10);
+                       if (errno) {
+                               rc = error(_("invalid timestamp"));
+                               goto exit;
+                       }
 
-                       if (!skip_prefix(end, " ", &str))
-                               return error(_("invalid Date line"));
+                       if (!skip_prefix(end, " ", &str)) {
+                               rc = error(_("invalid Date line"));
+                               goto exit;
+                       }
 
                        errno = 0;
                        tz = strtol(str, &end, 10);
-                       if (errno)
-                               return error(_("invalid timezone offset"));
+                       if (errno) {
+                               rc = error(_("invalid timezone offset"));
+                               goto exit;
+                       }
 
-                       if (*end)
-                               return error(_("invalid Date line"));
+                       if (*end) {
+                               rc = error(_("invalid Date line"));
+                               goto exit;
+                       }
 
                        /*
                         * mercurial's timezone is in seconds west of UTC,
@@ -920,9 +944,9 @@ static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
                fwrite(sb.buf, 1, sb.len, out);
                strbuf_reset(&sb);
        }
-
+exit:
        strbuf_release(&sb);
-       return 0;
+       return rc;
 }
 
 /**
@@ -987,6 +1011,7 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
 
        if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
                die_errno(_("failed to create directory '%s'"), state->dir);
+       delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 
        if (split_mail(state, patch_format, paths, keep_cr) < 0) {
                am_destroy(state);
@@ -1001,6 +1026,10 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
        write_state_bool(state, "sign", state->signoff);
        write_state_bool(state, "utf8", state->utf8);
 
+       if (state->allow_rerere_autoupdate)
+               write_state_bool(state, "rerere-autoupdate",
+                        state->allow_rerere_autoupdate == RERERE_AUTOUPDATE);
+
        switch (state->keep) {
        case KEEP_FALSE:
                str = "f";
@@ -1033,7 +1062,7 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
        }
        write_state_text(state, "scissors", str);
 
-       sq_quote_argv(&sb, state->git_apply_opts.argv, 0);
+       sq_quote_argv(&sb, state->git_apply_opts.argv);
        write_state_text(state, "apply-opt", sb.buf);
 
        if (state->rebasing)
@@ -1044,12 +1073,12 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
        if (!get_oid("HEAD", &curr_head)) {
                write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
                if (!state->rebasing)
-                       update_ref_oid("am", "ORIG_HEAD", &curr_head, NULL, 0,
-                                       UPDATE_REFS_DIE_ON_ERR);
+                       update_ref("am", "ORIG_HEAD", &curr_head, NULL, 0,
+                                  UPDATE_REFS_DIE_ON_ERR);
        } else {
                write_state_text(state, "abort-safety", "");
                if (!state->rebasing)
-                       delete_ref("ORIG_HEAD", NULL, 0);
+                       delete_ref(NULL, "ORIG_HEAD", NULL, 0);
        }
 
        /*
@@ -1071,17 +1100,10 @@ static void am_next(struct am_state *state)
 {
        struct object_id head;
 
-       free(state->author_name);
-       state->author_name = NULL;
-
-       free(state->author_email);
-       state->author_email = NULL;
-
-       free(state->author_date);
-       state->author_date = NULL;
-
-       free(state->msg);
-       state->msg = NULL;
+       FREE_AND_NULL(state->author_name);
+       FREE_AND_NULL(state->author_email);
+       FREE_AND_NULL(state->author_date);
+       FREE_AND_NULL(state->msg);
        state->msg_len = 0;
 
        unlink(am_path(state, "author-script"));
@@ -1089,6 +1111,7 @@ static void am_next(struct am_state *state)
 
        oidclr(&state->orig_commit);
        unlink(am_path(state, "original-commit"));
+       delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 
        if (!get_oid("HEAD", &head))
                write_state_text(state, "abort-safety", oid_to_hex(&head));
@@ -1117,51 +1140,14 @@ static const char *msgnum(const struct am_state *state)
  */
 static void refresh_and_write_cache(void)
 {
-       struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+       struct lock_file lock_file = LOCK_INIT;
 
-       hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
+       hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
        refresh_cache(REFRESH_QUIET);
-       if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
+       if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
                die(_("unable to write index file"));
 }
 
-/**
- * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
- * branch, returns 1 if there are entries in the index, 0 otherwise. If an
- * strbuf is provided, the space-separated list of files that differ will be
- * appended to it.
- */
-static int index_has_changes(struct strbuf *sb)
-{
-       struct object_id head;
-       int i;
-
-       if (!get_sha1_tree("HEAD", head.hash)) {
-               struct diff_options opt;
-
-               diff_setup(&opt);
-               DIFF_OPT_SET(&opt, EXIT_WITH_STATUS);
-               if (!sb)
-                       DIFF_OPT_SET(&opt, QUICK);
-               do_diff_cache(head.hash, &opt);
-               diffcore_std(&opt);
-               for (i = 0; sb && i < diff_queued_diff.nr; i++) {
-                       if (i)
-                               strbuf_addch(sb, ' ');
-                       strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path);
-               }
-               diff_flush(&opt);
-               return DIFF_OPT_TST(&opt, HAS_CHANGES) != 0;
-       } else {
-               for (i = 0; sb && i < active_nr; i++) {
-                       if (i)
-                               strbuf_addch(sb, ' ');
-                       strbuf_addstr(sb, active_cache[i]->name);
-               }
-               return !!active_nr;
-       }
-}
-
 /**
  * Dies with a user-friendly message on how to proceed after resolving the
  * problem. This message can be overridden with state->resolvemsg.
@@ -1181,33 +1167,6 @@ static void NORETURN die_user_resolve(const struct am_state *state)
        exit(128);
 }
 
-static void am_signoff(struct strbuf *sb)
-{
-       char *cp;
-       struct strbuf mine = STRBUF_INIT;
-
-       /* Does it end with our own sign-off? */
-       strbuf_addf(&mine, "\n%s%s\n",
-                   sign_off_header,
-                   fmt_name(getenv("GIT_COMMITTER_NAME"),
-                            getenv("GIT_COMMITTER_EMAIL")));
-       if (mine.len < sb->len &&
-           !strcmp(mine.buf, sb->buf + sb->len - mine.len))
-               goto exit; /* no need to duplicate */
-
-       /* Does it have any Signed-off-by: in the text */
-       for (cp = sb->buf;
-            cp && *cp && (cp = strstr(cp, sign_off_header)) != NULL;
-            cp = strchr(cp, '\n')) {
-               if (sb->buf == cp || cp[-1] == '\n')
-                       break;
-       }
-
-       strbuf_addstr(sb, mine.buf + !!cp);
-exit:
-       strbuf_release(&mine);
-}
-
 /**
  * Appends signoff to the "msg" field of the am_state.
  */
@@ -1216,7 +1175,7 @@ static void am_append_signoff(struct am_state *state)
        struct strbuf sb = STRBUF_INIT;
 
        strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
-       am_signoff(&sb);
+       append_signoff(&sb, 0, 0);
        state->msg = strbuf_detach(&sb, &state->msg_len);
 }
 
@@ -1276,12 +1235,8 @@ static int parse_mail(struct am_state *state, const char *mail)
                die("BUG: invalid value for state->scissors");
        }
 
-       mi.input = fopen(mail, "r");
-       if (!mi.input)
-               die("could not open input");
-       mi.output = fopen(am_path(state, "info"), "w");
-       if (!mi.output)
-               die("could not open output 'info'");
+       mi.input = xfopen(mail, "r");
+       mi.output = xfopen(am_path(state, "info"), "w");
        if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
                die("could not parse patch");
 
@@ -1313,7 +1268,7 @@ static int parse_mail(struct am_state *state, const char *mail)
        }
 
        if (is_empty_file(am_path(state, "patch"))) {
-               printf_ln(_("Patch is empty. Was it split wrong?"));
+               printf_ln(_("Patch is empty."));
                die_user_resolve(state);
        }
 
@@ -1321,9 +1276,6 @@ static int parse_mail(struct am_state *state, const char *mail)
        strbuf_addbuf(&msg, &mi.log_message);
        strbuf_stripspace(&msg, 0);
 
-       if (state->signoff)
-               am_signoff(&msg);
-
        assert(!state->author_name);
        state->author_name = strbuf_detach(&author_name, NULL);
 
@@ -1355,19 +1307,16 @@ static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
        struct strbuf sb = STRBUF_INIT;
        FILE *fp = xfopen(mail, "r");
        const char *x;
+       int ret = 0;
 
-       if (strbuf_getline_lf(&sb, fp))
-               return -1;
-
-       if (!skip_prefix(sb.buf, "From ", &x))
-               return -1;
-
-       if (get_oid_hex(x, commit_id) < 0)
-               return -1;
+       if (strbuf_getline_lf(&sb, fp) ||
+           !skip_prefix(sb.buf, "From ", &x) ||
+           get_oid_hex(x, commit_id) < 0)
+               ret = -1;
 
        strbuf_release(&sb);
        fclose(fp);
-       return 0;
+       return ret;
 }
 
 /**
@@ -1376,40 +1325,33 @@ static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
  */
 static void get_commit_info(struct am_state *state, struct commit *commit)
 {
-       const char *buffer, *ident_line, *author_date, *msg;
+       const char *buffer, *ident_line, *msg;
        size_t ident_len;
-       struct ident_split ident_split;
-       struct strbuf sb = STRBUF_INIT;
+       struct ident_split id;
 
        buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
 
        ident_line = find_commit_header(buffer, "author", &ident_len);
 
-       if (split_ident_line(&ident_split, ident_line, ident_len) < 0) {
-               strbuf_add(&sb, ident_line, ident_len);
-               die(_("invalid ident line: %s"), sb.buf);
-       }
+       if (split_ident_line(&id, ident_line, ident_len) < 0)
+               die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);
 
        assert(!state->author_name);
-       if (ident_split.name_begin) {
-               strbuf_add(&sb, ident_split.name_begin,
-                       ident_split.name_end - ident_split.name_begin);
-               state->author_name = strbuf_detach(&sb, NULL);
-       } else
+       if (id.name_begin)
+               state->author_name =
+                       xmemdupz(id.name_begin, id.name_end - id.name_begin);
+       else
                state->author_name = xstrdup("");
 
        assert(!state->author_email);
-       if (ident_split.mail_begin) {
-               strbuf_add(&sb, ident_split.mail_begin,
-                       ident_split.mail_end - ident_split.mail_begin);
-               state->author_email = strbuf_detach(&sb, NULL);
-       } else
+       if (id.mail_begin)
+               state->author_email =
+                       xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
+       else
                state->author_email = xstrdup("");
 
-       author_date = show_ident_date(&ident_split, DATE_MODE(NORMAL));
-       strbuf_addstr(&sb, author_date);
        assert(!state->author_date);
-       state->author_date = strbuf_detach(&sb, NULL);
+       state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));
 
        assert(!state->msg);
        msg = strstr(buffer, "\n\n");
@@ -1417,6 +1359,7 @@ static void get_commit_info(struct am_state *state, struct commit *commit)
                die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
        state->msg = xstrdup(msg + 2);
        state->msg_len = strlen(state->msg);
+       unuse_commit_buffer(commit, buffer);
 }
 
 /**
@@ -1435,8 +1378,8 @@ static void write_commit_patch(const struct am_state *state, struct commit *comm
        rev_info.show_root_diff = 1;
        rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
        rev_info.no_commit_id = 1;
-       DIFF_OPT_SET(&rev_info.diffopt, BINARY);
-       DIFF_OPT_SET(&rev_info.diffopt, FULL_INDEX);
+       rev_info.diffopt.flags.binary = 1;
+       rev_info.diffopt.flags.full_index = 1;
        rev_info.diffopt.use_color = 0;
        rev_info.diffopt.file = fp;
        rev_info.diffopt.close_file = 1;
@@ -1456,10 +1399,10 @@ static void write_index_patch(const struct am_state *state)
        struct rev_info rev_info;
        FILE *fp;
 
-       if (!get_sha1_tree("HEAD", head.hash))
-               tree = lookup_tree(head.hash);
+       if (!get_oid_tree("HEAD", &head))
+               tree = lookup_tree(&head);
        else
-               tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
+               tree = lookup_tree(the_hash_algo->empty_tree);
 
        fp = xfopen(am_path(state, "patch"), "w");
        init_revisions(&rev_info, NULL);
@@ -1492,7 +1435,7 @@ static int parse_mail_rebase(struct am_state *state, const char *mail)
        if (get_mail_commit_oid(&commit_oid, mail) < 0)
                die(_("could not parse %s"), mail);
 
-       commit = lookup_commit_or_die(commit_oid.hash, mail);
+       commit = lookup_commit_or_die(&commit_oid, mail);
 
        get_commit_info(state, commit);
 
@@ -1500,6 +1443,8 @@ static int parse_mail_rebase(struct am_state *state, const char *mail)
 
        oidcpy(&state->orig_commit, &commit_oid);
        write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
+       update_ref("am", "REBASE_HEAD", &commit_oid,
+                  NULL, REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
 
        return 0;
 }
@@ -1514,11 +1459,10 @@ static int run_apply(const struct am_state *state, const char *index_file)
        struct argv_array apply_opts = ARGV_ARRAY_INIT;
        struct apply_state apply_state;
        int res, opts_left;
-       static struct lock_file lock_file;
        int force_apply = 0;
        int options = 0;
 
-       if (init_apply_state(&apply_state, NULL, &lock_file))
+       if (init_apply_state(&apply_state, NULL))
                die("BUG: init_apply_state() failed");
 
        argv_array_push(&apply_opts, "apply");
@@ -1622,7 +1566,7 @@ static int fall_back_threeway(const struct am_state *state, const char *index_pa
                init_revisions(&rev_info, NULL);
                rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
                diff_opt_parse(&rev_info.diffopt, &diff_filter_str, 1, rev_info.prefix);
-               add_pending_sha1(&rev_info, "HEAD", our_tree.hash, 0);
+               add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
                diff_setup_done(&rev_info.diffopt);
                run_diff_index(&rev_info, 1);
        }
@@ -1685,9 +1629,9 @@ static void do_commit(const struct am_state *state)
        if (write_cache_as_tree(tree.hash, 0, NULL))
                die(_("git write-tree failed to write a tree"));
 
-       if (!get_sha1_commit("HEAD", parent.hash)) {
+       if (!get_oid_commit("HEAD", &parent)) {
                old_oid = &parent;
-               commit_list_insert(lookup_commit(parent.hash), &parents);
+               commit_list_insert(lookup_commit(&parent), &parents);
        } else {
                old_oid = NULL;
                say(state, stderr, _("applying to an empty history"));
@@ -1701,8 +1645,8 @@ static void do_commit(const struct am_state *state)
                setenv("GIT_COMMITTER_DATE",
                        state->ignore_date ? "" : state->author_date, 1);
 
-       if (commit_tree(state->msg, state->msg_len, tree.hash, parents, commit.hash,
-                               author, state->sign_commit))
+       if (commit_tree(state->msg, state->msg_len, &tree, parents, &commit,
+                       author, state->sign_commit))
                die(_("failed to write commit object"));
 
        reflog_msg = getenv("GIT_REFLOG_ACTION");
@@ -1712,8 +1656,8 @@ static void do_commit(const struct am_state *state)
        strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
                        state->msg);
 
-       update_ref_oid(sb.buf, "HEAD", &commit, old_oid, 0,
-                       UPDATE_REFS_DIE_ON_ERR);
+       update_ref(sb.buf, "HEAD", &commit, old_oid, 0,
+                  UPDATE_REFS_DIE_ON_ERR);
 
        if (state->rebasing) {
                FILE *fp = xfopen(am_path(state, "rewritten"), "a");
@@ -1848,6 +1792,9 @@ static void am_run(struct am_state *state, int resume)
                        if (skip)
                                goto next; /* mail should be skipped */
 
+                       if (state->signoff)
+                               am_append_signoff(state);
+
                        write_author_script(state);
                        write_commit_msg(state);
                }
@@ -1888,8 +1835,7 @@ static void am_run(struct am_state *state, int resume)
                        git_config_get_bool("advice.amworkdir", &advice_amworkdir);
 
                        if (advice_amworkdir)
-                               printf_ln(_("The copy of the patch that failed is found in: %s"),
-                                               am_path(state, "patch"));
+                               printf_ln(_("Use 'git am --show-current-patch' to see the failed patch"));
 
                        die_user_resolve(state);
                }
@@ -1941,7 +1887,8 @@ static void am_resolve(struct am_state *state)
 
        if (unmerged_cache()) {
                printf_ln(_("You still have unmerged paths in your index.\n"
-                       "Did you forget to use 'git add'?"));
+                       "You should 'git add' each file with resolved conflicts to mark them as such.\n"
+                       "You might run `git rm` on a file to accept \"deleted by them\" for it."));
                die_user_resolve(state);
        }
 
@@ -1968,15 +1915,14 @@ static void am_resolve(struct am_state *state)
  */
 static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
 {
-       struct lock_file *lock_file;
+       struct lock_file lock_file = LOCK_INIT;
        struct unpack_trees_options opts;
        struct tree_desc t[2];
 
        if (parse_tree(head) || parse_tree(remote))
                return -1;
 
-       lock_file = xcalloc(1, sizeof(struct lock_file));
-       hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
+       hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
        refresh_cache(REFRESH_QUIET);
 
@@ -1992,11 +1938,11 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
        init_tree_desc(&t[1], remote->buffer, remote->size);
 
        if (unpack_trees(2, t, &opts)) {
-               rollback_lock_file(lock_file);
+               rollback_lock_file(&lock_file);
                return -1;
        }
 
-       if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
+       if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
                die(_("unable to write new index file"));
 
        return 0;
@@ -2008,15 +1954,14 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
  */
 static int merge_tree(struct tree *tree)
 {
-       struct lock_file *lock_file;
+       struct lock_file lock_file = LOCK_INIT;
        struct unpack_trees_options opts;
        struct tree_desc t[1];
 
        if (parse_tree(tree))
                return -1;
 
-       lock_file = xcalloc(1, sizeof(struct lock_file));
-       hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
+       hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
        memset(&opts, 0, sizeof(opts));
        opts.head_idx = 1;
@@ -2027,11 +1972,11 @@ static int merge_tree(struct tree *tree)
        init_tree_desc(&t[0], tree->buffer, tree->size);
 
        if (unpack_trees(1, t, &opts)) {
-               rollback_lock_file(lock_file);
+               rollback_lock_file(&lock_file);
                return -1;
        }
 
-       if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
+       if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
                die(_("unable to write new index file"));
 
        return 0;
@@ -2046,11 +1991,11 @@ static int clean_index(const struct object_id *head, const struct object_id *rem
        struct tree *head_tree, *remote_tree, *index_tree;
        struct object_id index;
 
-       head_tree = parse_tree_indirect(head->hash);
+       head_tree = parse_tree_indirect(head);
        if (!head_tree)
                return error(_("Could not parse object '%s'."), oid_to_hex(head));
 
-       remote_tree = parse_tree_indirect(remote->hash);
+       remote_tree = parse_tree_indirect(remote);
        if (!remote_tree)
                return error(_("Could not parse object '%s'."), oid_to_hex(remote));
 
@@ -2062,7 +2007,7 @@ static int clean_index(const struct object_id *head, const struct object_id *rem
        if (write_cache_as_tree(index.hash, 0, NULL))
                return -1;
 
-       index_tree = parse_tree_indirect(index.hash);
+       index_tree = parse_tree_indirect(&index);
        if (!index_tree)
                return error(_("Could not parse object '%s'."), oid_to_hex(&index));
 
@@ -2127,6 +2072,7 @@ static int safe_to_abort(const struct am_state *state)
                        die(_("could not parse %s"), am_path(state, "abort-safety"));
        } else
                oidclr(&abort_safety);
+       strbuf_release(&sb);
 
        if (get_oid("HEAD", &head))
                oidclr(&head);
@@ -2156,8 +2102,8 @@ static void am_abort(struct am_state *state)
 
        am_rerere_clear();
 
-       curr_branch = resolve_refdup("HEAD", 0, curr_head.hash, NULL);
-       has_curr_head = !is_null_oid(&curr_head);
+       curr_branch = resolve_refdup("HEAD", 0, &curr_head, NULL);
+       has_curr_head = curr_branch && !is_null_oid(&curr_head);
        if (!has_curr_head)
                hashcpy(curr_head.hash, EMPTY_TREE_SHA1_BIN);
 
@@ -2168,16 +2114,44 @@ static void am_abort(struct am_state *state)
        clean_index(&curr_head, &orig_head);
 
        if (has_orig_head)
-               update_ref_oid("am --abort", "HEAD", &orig_head,
-                               has_curr_head ? &curr_head : NULL, 0,
-                               UPDATE_REFS_DIE_ON_ERR);
+               update_ref("am --abort", "HEAD", &orig_head,
+                          has_curr_head ? &curr_head : NULL, 0,
+                          UPDATE_REFS_DIE_ON_ERR);
        else if (curr_branch)
-               delete_ref(curr_branch, NULL, REF_NODEREF);
+               delete_ref(NULL, curr_branch, NULL, REF_NO_DEREF);
 
        free(curr_branch);
        am_destroy(state);
 }
 
+static int show_patch(struct am_state *state)
+{
+       struct strbuf sb = STRBUF_INIT;
+       const char *patch_path;
+       int len;
+
+       if (!is_null_oid(&state->orig_commit)) {
+               const char *av[4] = { "show", NULL, "--", NULL };
+               char *new_oid_str;
+               int ret;
+
+               av[1] = new_oid_str = xstrdup(oid_to_hex(&state->orig_commit));
+               ret = run_command_v_opt(av, RUN_GIT_CMD);
+               free(new_oid_str);
+               return ret;
+       }
+
+       patch_path = am_path(state, msgnum(state));
+       len = strbuf_read_file(&sb, patch_path, 0);
+       if (len < 0)
+               die_errno(_("failed to read '%s'"), patch_path);
+
+       setup_pager();
+       write_in_full(1, sb.buf, sb.len);
+       strbuf_release(&sb);
+       return 0;
+}
+
 /**
  * parse_options() callback that validates and sets opt->value to the
  * PATCH_FORMAT_* enum value corresponding to `arg`.
@@ -2206,7 +2180,9 @@ enum resume_mode {
        RESUME_APPLY,
        RESUME_RESOLVED,
        RESUME_SKIP,
-       RESUME_ABORT
+       RESUME_ABORT,
+       RESUME_QUIT,
+       RESUME_SHOW_PATCH
 };
 
 static int git_am_config(const char *k, const char *v, void *cb)
@@ -2228,6 +2204,7 @@ int cmd_am(int argc, const char **argv, const char *prefix)
        int patch_format = PATCH_FORMAT_UNKNOWN;
        enum resume_mode resume = RESUME_FALSE;
        int in_progress;
+       int ret = 0;
 
        const char * const usage[] = {
                N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
@@ -2306,6 +2283,12 @@ int cmd_am(int argc, const char **argv, const char *prefix)
                OPT_CMDMODE(0, "abort", &resume,
                        N_("restore the original branch and abort the patching operation."),
                        RESUME_ABORT),
+               OPT_CMDMODE(0, "quit", &resume,
+                       N_("abort the patching operation but keep HEAD where it is."),
+                       RESUME_QUIT),
+               OPT_CMDMODE(0, "show-current-patch", &resume,
+                       N_("show the patch being applied."),
+                       RESUME_SHOW_PATCH),
                OPT_BOOL(0, "committer-date-is-author-date",
                        &state.committer_date_is_author_date,
                        N_("lie about committer date")),
@@ -2320,9 +2303,12 @@ int cmd_am(int argc, const char **argv, const char *prefix)
                OPT_END()
        };
 
+       if (argc == 2 && !strcmp(argv[1], "-h"))
+               usage_with_options(usage, options);
+
        git_config(git_am_config, NULL);
 
-       am_state_init(&state, git_path("rebase-apply"));
+       am_state_init(&state);
 
        in_progress = am_in_progress(&state);
        if (in_progress)
@@ -2371,7 +2357,7 @@ int cmd_am(int argc, const char **argv, const char *prefix)
                 * stray directories.
                 */
                if (file_exists(state.dir) && !state.rebasing) {
-                       if (resume == RESUME_ABORT) {
+                       if (resume == RESUME_ABORT || resume == RESUME_QUIT) {
                                am_destroy(&state);
                                am_state_release(&state);
                                return 0;
@@ -2413,11 +2399,18 @@ int cmd_am(int argc, const char **argv, const char *prefix)
        case RESUME_ABORT:
                am_abort(&state);
                break;
+       case RESUME_QUIT:
+               am_rerere_clear();
+               am_destroy(&state);
+               break;
+       case RESUME_SHOW_PATCH:
+               ret = show_patch(&state);
+               break;
        default:
                die("BUG: invalid resume value");
        }
 
        am_state_release(&state);
 
-       return 0;
+       return ret;
 }