git-log.txt,rev-list-options.txt: put option blocks in proper order
[gitweb.git] / builtin / notes.c
index feb710ac4ada96339e42fe5838cf137e9ae4f12e..4d5556e2cb5bccaf0100d9f5019e1a1c493e35e7 100644 (file)
 #include "exec_cmd.h"
 #include "run-command.h"
 #include "parse-options.h"
+#include "string-list.h"
+#include "notes-merge.h"
 
 static const char * const git_notes_usage[] = {
+       "git notes [--ref <notes_ref>] [list [<object>]]",
+       "git notes [--ref <notes_ref>] add [-f] [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]",
+       "git notes [--ref <notes_ref>] copy [-f] <from-object> <to-object>",
+       "git notes [--ref <notes_ref>] append [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]",
+       "git notes [--ref <notes_ref>] edit [<object>]",
+       "git notes [--ref <notes_ref>] show [<object>]",
+       "git notes [--ref <notes_ref>] merge [-v | -q] [-s <strategy> ] <notes_ref>",
+       "git notes merge --commit [-v | -q]",
+       "git notes merge --abort [-v | -q]",
+       "git notes [--ref <notes_ref>] remove [<object>]",
+       "git notes [--ref <notes_ref>] prune [-n | -v]",
+       "git notes [--ref <notes_ref>] get-ref",
+       NULL
+};
+
+static const char * const git_notes_list_usage[] = {
        "git notes [list [<object>]]",
-       "git notes add [-f] [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]",
-       "git notes copy [-f] <from-object> <to-object>",
-       "git notes append [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]",
+       NULL
+};
+
+static const char * const git_notes_add_usage[] = {
+       "git notes add [<options>] [<object>]",
+       NULL
+};
+
+static const char * const git_notes_copy_usage[] = {
+       "git notes copy [<options>] <from-object> <to-object>",
+       "git notes copy --stdin [<from-object> <to-object>]...",
+       NULL
+};
+
+static const char * const git_notes_append_usage[] = {
+       "git notes append [<options>] [<object>]",
+       NULL
+};
+
+static const char * const git_notes_edit_usage[] = {
        "git notes edit [<object>]",
+       NULL
+};
+
+static const char * const git_notes_show_usage[] = {
        "git notes show [<object>]",
+       NULL
+};
+
+static const char * const git_notes_merge_usage[] = {
+       "git notes merge [<options>] <notes_ref>",
+       "git notes merge --commit [<options>]",
+       "git notes merge --abort [<options>]",
+       NULL
+};
+
+static const char * const git_notes_remove_usage[] = {
        "git notes remove [<object>]",
-       "git notes prune",
+       NULL
+};
+
+static const char * const git_notes_prune_usage[] = {
+       "git notes prune [<options>]",
+       NULL
+};
+
+static const char * const git_notes_get_ref_usage[] = {
+       "git notes get-ref",
        NULL
 };
 
@@ -41,6 +100,16 @@ struct msg_arg {
        struct strbuf buf;
 };
 
+static void expand_notes_ref(struct strbuf *sb)
+{
+       if (!prefixcmp(sb->buf, "refs/notes/"))
+               return; /* we're happy */
+       else if (!prefixcmp(sb->buf, "notes/"))
+               strbuf_insert(sb, 0, "refs/", 5);
+       else
+               strbuf_insert(sb, 0, "refs/notes/", 11);
+}
+
 static int list_each_note(const unsigned char *object_sha1,
                const unsigned char *note_sha1, char *note_path,
                void *cb_data)
@@ -229,16 +298,17 @@ static int parse_reedit_arg(const struct option *opt, const char *arg, int unset
        return parse_reuse_arg(opt, arg, unset);
 }
 
-int commit_notes(struct notes_tree *t, const char *msg)
+void commit_notes(struct notes_tree *t, const char *msg)
 {
-       struct commit_list *parent;
-       unsigned char tree_sha1[20], prev_commit[20], new_commit[20];
        struct strbuf buf = STRBUF_INIT;
+       unsigned char commit_sha1[20];
 
        if (!t)
                t = &default_notes_tree;
        if (!t->initialized || !t->ref || !*t->ref)
                die("Cannot commit uninitialized/unreferenced notes tree");
+       if (!t->dirty)
+               return; /* don't have to commit an unchanged tree */
 
        /* Prepare commit message and reflog message */
        strbuf_addstr(&buf, "notes: "); /* commit message starts at index 7 */
@@ -246,43 +316,227 @@ int commit_notes(struct notes_tree *t, const char *msg)
        if (buf.buf[buf.len - 1] != '\n')
                strbuf_addch(&buf, '\n'); /* Make sure msg ends with newline */
 
-       /* Convert notes tree to tree object */
-       if (write_notes_tree(t, tree_sha1))
-               die("Failed to write current notes tree to database");
+       create_notes_commit(t, NULL, buf.buf + 7, commit_sha1);
+       update_ref(buf.buf, t->ref, commit_sha1, NULL, 0, DIE_ON_ERR);
+
+       strbuf_release(&buf);
+}
+
+combine_notes_fn parse_combine_notes_fn(const char *v)
+{
+       if (!strcasecmp(v, "overwrite"))
+               return combine_notes_overwrite;
+       else if (!strcasecmp(v, "ignore"))
+               return combine_notes_ignore;
+       else if (!strcasecmp(v, "concatenate"))
+               return combine_notes_concatenate;
+       else if (!strcasecmp(v, "cat_sort_uniq"))
+               return combine_notes_cat_sort_uniq;
+       else
+               return NULL;
+}
+
+static int notes_rewrite_config(const char *k, const char *v, void *cb)
+{
+       struct notes_rewrite_cfg *c = cb;
+       if (!prefixcmp(k, "notes.rewrite.") && !strcmp(k+14, c->cmd)) {
+               c->enabled = git_config_bool(k, v);
+               return 0;
+       } else if (!c->mode_from_env && !strcmp(k, "notes.rewritemode")) {
+               if (!v)
+                       config_error_nonbool(k);
+               c->combine = parse_combine_notes_fn(v);
+               if (!c->combine) {
+                       error("Bad notes.rewriteMode value: '%s'", v);
+                       return 1;
+               }
+               return 0;
+       } else if (!c->refs_from_env && !strcmp(k, "notes.rewriteref")) {
+               /* note that a refs/ prefix is implied in the
+                * underlying for_each_glob_ref */
+               if (!prefixcmp(v, "refs/notes/"))
+                       string_list_add_refs_by_glob(c->refs, v);
+               else
+                       warning("Refusing to rewrite notes in %s"
+                               " (outside of refs/notes/)", v);
+               return 0;
+       }
+
+       return 0;
+}
+
+
+struct notes_rewrite_cfg *init_copy_notes_for_rewrite(const char *cmd)
+{
+       struct notes_rewrite_cfg *c = xmalloc(sizeof(struct notes_rewrite_cfg));
+       const char *rewrite_mode_env = getenv(GIT_NOTES_REWRITE_MODE_ENVIRONMENT);
+       const char *rewrite_refs_env = getenv(GIT_NOTES_REWRITE_REF_ENVIRONMENT);
+       c->cmd = cmd;
+       c->enabled = 1;
+       c->combine = combine_notes_concatenate;
+       c->refs = xcalloc(1, sizeof(struct string_list));
+       c->refs->strdup_strings = 1;
+       c->refs_from_env = 0;
+       c->mode_from_env = 0;
+       if (rewrite_mode_env) {
+               c->mode_from_env = 1;
+               c->combine = parse_combine_notes_fn(rewrite_mode_env);
+               if (!c->combine)
+                       error("Bad " GIT_NOTES_REWRITE_MODE_ENVIRONMENT
+                             " value: '%s'", rewrite_mode_env);
+       }
+       if (rewrite_refs_env) {
+               c->refs_from_env = 1;
+               string_list_add_refs_from_colon_sep(c->refs, rewrite_refs_env);
+       }
+       git_config(notes_rewrite_config, c);
+       if (!c->enabled || !c->refs->nr) {
+               string_list_clear(c->refs, 0);
+               free(c->refs);
+               free(c);
+               return NULL;
+       }
+       c->trees = load_notes_trees(c->refs);
+       string_list_clear(c->refs, 0);
+       free(c->refs);
+       return c;
+}
+
+int copy_note_for_rewrite(struct notes_rewrite_cfg *c,
+                         const unsigned char *from_obj, const unsigned char *to_obj)
+{
+       int ret = 0;
+       int i;
+       for (i = 0; c->trees[i]; i++)
+               ret = copy_note(c->trees[i], from_obj, to_obj, 1, c->combine) || ret;
+       return ret;
+}
+
+void finish_copy_notes_for_rewrite(struct notes_rewrite_cfg *c)
+{
+       int i;
+       for (i = 0; c->trees[i]; i++) {
+               commit_notes(c->trees[i], "Notes added by 'git notes copy'");
+               free_notes(c->trees[i]);
+       }
+       free(c->trees);
+       free(c);
+}
 
-       /* Create new commit for the tree object */
-       if (!read_ref(t->ref, prev_commit)) { /* retrieve parent commit */
-               parent = xmalloc(sizeof(*parent));
-               parent->item = lookup_commit(prev_commit);
-               parent->next = NULL;
+int notes_copy_from_stdin(int force, const char *rewrite_cmd)
+{
+       struct strbuf buf = STRBUF_INIT;
+       struct notes_rewrite_cfg *c = NULL;
+       struct notes_tree *t = NULL;
+       int ret = 0;
+
+       if (rewrite_cmd) {
+               c = init_copy_notes_for_rewrite(rewrite_cmd);
+               if (!c)
+                       return 0;
        } else {
-               hashclr(prev_commit);
-               parent = NULL;
+               init_notes(NULL, NULL, NULL, 0);
+               t = &default_notes_tree;
        }
-       if (commit_tree(buf.buf + 7, tree_sha1, parent, new_commit, NULL))
-               die("Failed to commit notes tree to database");
 
-       /* Update notes ref with new commit */
-       update_ref(buf.buf, t->ref, new_commit, prev_commit, 0, DIE_ON_ERR);
+       while (strbuf_getline(&buf, stdin, '\n') != EOF) {
+               unsigned char from_obj[20], to_obj[20];
+               struct strbuf **split;
+               int err;
+
+               split = strbuf_split(&buf, ' ');
+               if (!split[0] || !split[1])
+                       die("Malformed input line: '%s'.", buf.buf);
+               strbuf_rtrim(split[0]);
+               strbuf_rtrim(split[1]);
+               if (get_sha1(split[0]->buf, from_obj))
+                       die("Failed to resolve '%s' as a valid ref.", split[0]->buf);
+               if (get_sha1(split[1]->buf, to_obj))
+                       die("Failed to resolve '%s' as a valid ref.", split[1]->buf);
+
+               if (rewrite_cmd)
+                       err = copy_note_for_rewrite(c, from_obj, to_obj);
+               else
+                       err = copy_note(t, from_obj, to_obj, force,
+                                       combine_notes_overwrite);
+
+               if (err) {
+                       error("Failed to copy notes from '%s' to '%s'",
+                             split[0]->buf, split[1]->buf);
+                       ret = 1;
+               }
 
-       strbuf_release(&buf);
-       return 0;
+               strbuf_list_free(split);
+       }
+
+       if (!rewrite_cmd) {
+               commit_notes(t, "Notes added by 'git notes copy'");
+               free_notes(t);
+       } else {
+               finish_copy_notes_for_rewrite(c);
+       }
+       return ret;
 }
 
-int cmd_notes(int argc, const char **argv, const char *prefix)
+static struct notes_tree *init_notes_check(const char *subcommand)
 {
        struct notes_tree *t;
-       unsigned char object[20], from_obj[20], new_note[20];
+       init_notes(NULL, NULL, NULL, 0);
+       t = &default_notes_tree;
+
+       if (prefixcmp(t->ref, "refs/notes/"))
+               die("Refusing to %s notes in %s (outside of refs/notes/)",
+                   subcommand, t->ref);
+       return t;
+}
+
+static int list(int argc, const char **argv, const char *prefix)
+{
+       struct notes_tree *t;
+       unsigned char object[20];
        const unsigned char *note;
+       int retval = -1;
+       struct option options[] = {
+               OPT_END()
+       };
+
+       if (argc)
+               argc = parse_options(argc, argv, prefix, options,
+                                    git_notes_list_usage, 0);
+
+       if (1 < argc) {
+               error("too many parameters");
+               usage_with_options(git_notes_list_usage, options);
+       }
+
+       t = init_notes_check("list");
+       if (argc) {
+               if (get_sha1(argv[0], object))
+                       die("Failed to resolve '%s' as a valid ref.", argv[0]);
+               note = get_note(t, object);
+               if (note) {
+                       puts(sha1_to_hex(note));
+                       retval = 0;
+               } else
+                       retval = error("No note found for object %s.",
+                                      sha1_to_hex(object));
+       } else
+               retval = for_each_note(t, 0, list_each_note, NULL);
+
+       free_notes(t);
+       return retval;
+}
+
+static int add(int argc, const char **argv, const char *prefix)
+{
+       int retval = 0, force = 0;
        const char *object_ref;
+       struct notes_tree *t;
+       unsigned char object[20], new_note[20];
        char logmsg[100];
-
-       int list = 0, add = 0, copy = 0, append = 0, edit = 0, show = 0,
-           remove = 0, prune = 0, force = 0;
-       int given_object = 0, i = 1, retval = 0;
+       const unsigned char *note;
        struct msg_arg msg = { 0, 0, STRBUF_INIT };
        struct option options[] = {
-               OPT_GROUP("Notes contents options"),
                { OPTION_CALLBACK, 'm', "message", &msg, "MSG",
                        "note contents as a string", PARSE_OPT_NONEG,
                        parse_msg_arg},
@@ -295,161 +549,529 @@ int cmd_notes(int argc, const char **argv, const char *prefix)
                { OPTION_CALLBACK, 'C', "reuse-message", &msg, "OBJECT",
                        "reuse specified note object", PARSE_OPT_NONEG,
                        parse_reuse_arg},
-               OPT_GROUP("Other options"),
-               OPT_BOOLEAN('f', "force", &force, "replace existing notes"),
+               OPT__FORCE(&force, "replace existing notes"),
                OPT_END()
        };
 
-       git_config(git_default_config, NULL);
+       argc = parse_options(argc, argv, prefix, options, git_notes_add_usage,
+                            0);
 
-       argc = parse_options(argc, argv, prefix, options, git_notes_usage, 0);
-
-       if (argc && !strcmp(argv[0], "list"))
-               list = 1;
-       else if (argc && !strcmp(argv[0], "add"))
-               add = 1;
-       else if (argc && !strcmp(argv[0], "copy"))
-               copy = 1;
-       else if (argc && !strcmp(argv[0], "append"))
-               append = 1;
-       else if (argc && !strcmp(argv[0], "edit"))
-               edit = 1;
-       else if (argc && !strcmp(argv[0], "show"))
-               show = 1;
-       else if (argc && !strcmp(argv[0], "remove"))
-               remove = 1;
-       else if (argc && !strcmp(argv[0], "prune"))
-               prune = 1;
-       else if (!argc) {
-               list = 1; /* Default to 'list' if no other subcommand given */
-               i = 0;
-       }
-
-       if (list + add + copy + append + edit + show + remove + prune != 1)
-               usage_with_options(git_notes_usage, options);
+       if (1 < argc) {
+               error("too many parameters");
+               usage_with_options(git_notes_add_usage, options);
+       }
 
-       if (msg.given && !(add || append || edit)) {
-               error("cannot use -m/-F/-c/-C options with %s subcommand.",
-                     argv[0]);
-               usage_with_options(git_notes_usage, options);
+       object_ref = argc ? argv[0] : "HEAD";
+
+       if (get_sha1(object_ref, object))
+               die("Failed to resolve '%s' as a valid ref.", object_ref);
+
+       t = init_notes_check("add");
+       note = get_note(t, object);
+
+       if (note) {
+               if (!force) {
+                       retval = error("Cannot add notes. Found existing notes "
+                                      "for object %s. Use '-f' to overwrite "
+                                      "existing notes", sha1_to_hex(object));
+                       goto out;
+               }
+               fprintf(stderr, "Overwriting existing notes for object %s\n",
+                       sha1_to_hex(object));
        }
 
-       if (msg.given && edit) {
-               fprintf(stderr, "The -m/-F/-c/-C options have been deprecated "
-                       "for the 'edit' subcommand.\n"
-                       "Please use 'git notes add -f -m/-F/-c/-C' instead.\n");
+       create_note(object, &msg, 0, note, new_note);
+
+       if (is_null_sha1(new_note))
+               remove_note(t, object);
+       else if (add_note(t, object, new_note, combine_notes_overwrite))
+               die("BUG: combine_notes_overwrite failed");
+
+       snprintf(logmsg, sizeof(logmsg), "Notes %s by 'git notes %s'",
+                is_null_sha1(new_note) ? "removed" : "added", "add");
+       commit_notes(t, logmsg);
+out:
+       free_notes(t);
+       strbuf_release(&(msg.buf));
+       return retval;
+}
+
+static int copy(int argc, const char **argv, const char *prefix)
+{
+       int retval = 0, force = 0, from_stdin = 0;
+       const unsigned char *from_note, *note;
+       const char *object_ref;
+       unsigned char object[20], from_obj[20];
+       struct notes_tree *t;
+       const char *rewrite_cmd = NULL;
+       struct option options[] = {
+               OPT__FORCE(&force, "replace existing notes"),
+               OPT_BOOLEAN(0, "stdin", &from_stdin, "read objects from stdin"),
+               OPT_STRING(0, "for-rewrite", &rewrite_cmd, "command",
+                          "load rewriting config for <command> (implies "
+                          "--stdin)"),
+               OPT_END()
+       };
+
+       argc = parse_options(argc, argv, prefix, options, git_notes_copy_usage,
+                            0);
+
+       if (from_stdin || rewrite_cmd) {
+               if (argc) {
+                       error("too many parameters");
+                       usage_with_options(git_notes_copy_usage, options);
+               } else {
+                       return notes_copy_from_stdin(force, rewrite_cmd);
+               }
        }
 
-       if (force && !(add || copy)) {
-               error("cannot use -f option with %s subcommand.", argv[0]);
-               usage_with_options(git_notes_usage, options);
+       if (argc < 2) {
+               error("too few parameters");
+               usage_with_options(git_notes_copy_usage, options);
+       }
+       if (2 < argc) {
+               error("too many parameters");
+               usage_with_options(git_notes_copy_usage, options);
        }
 
-       if (copy) {
-               const char *from_ref;
-               if (argc < 3) {
-                       error("too few parameters");
-                       usage_with_options(git_notes_usage, options);
+       if (get_sha1(argv[0], from_obj))
+               die("Failed to resolve '%s' as a valid ref.", argv[0]);
+
+       object_ref = 1 < argc ? argv[1] : "HEAD";
+
+       if (get_sha1(object_ref, object))
+               die("Failed to resolve '%s' as a valid ref.", object_ref);
+
+       t = init_notes_check("copy");
+       note = get_note(t, object);
+
+       if (note) {
+               if (!force) {
+                       retval = error("Cannot copy notes. Found existing "
+                                      "notes for object %s. Use '-f' to "
+                                      "overwrite existing notes",
+                                      sha1_to_hex(object));
+                       goto out;
                }
-               from_ref = argv[i++];
-               if (get_sha1(from_ref, from_obj))
-                       die("Failed to resolve '%s' as a valid ref.", from_ref);
+               fprintf(stderr, "Overwriting existing notes for object %s\n",
+                       sha1_to_hex(object));
+       }
+
+       from_note = get_note(t, from_obj);
+       if (!from_note) {
+               retval = error("Missing notes on source object %s. Cannot "
+                              "copy.", sha1_to_hex(from_obj));
+               goto out;
        }
 
-       given_object = argc > i;
-       object_ref = given_object ? argv[i++] : "HEAD";
+       if (add_note(t, object, from_note, combine_notes_overwrite))
+               die("BUG: combine_notes_overwrite failed");
+       commit_notes(t, "Notes added by 'git notes copy'");
+out:
+       free_notes(t);
+       return retval;
+}
+
+static int append_edit(int argc, const char **argv, const char *prefix)
+{
+       const char *object_ref;
+       struct notes_tree *t;
+       unsigned char object[20], new_note[20];
+       const unsigned char *note;
+       char logmsg[100];
+       const char * const *usage;
+       struct msg_arg msg = { 0, 0, STRBUF_INIT };
+       struct option options[] = {
+               { OPTION_CALLBACK, 'm', "message", &msg, "MSG",
+                       "note contents as a string", PARSE_OPT_NONEG,
+                       parse_msg_arg},
+               { OPTION_CALLBACK, 'F', "file", &msg, "FILE",
+                       "note contents in a file", PARSE_OPT_NONEG,
+                       parse_file_arg},
+               { OPTION_CALLBACK, 'c', "reedit-message", &msg, "OBJECT",
+                       "reuse and edit specified note object", PARSE_OPT_NONEG,
+                       parse_reedit_arg},
+               { OPTION_CALLBACK, 'C', "reuse-message", &msg, "OBJECT",
+                       "reuse specified note object", PARSE_OPT_NONEG,
+                       parse_reuse_arg},
+               OPT_END()
+       };
+       int edit = !strcmp(argv[0], "edit");
+
+       usage = edit ? git_notes_edit_usage : git_notes_append_usage;
+       argc = parse_options(argc, argv, prefix, options, usage,
+                            PARSE_OPT_KEEP_ARGV0);
 
-       if (argc > i || (prune && given_object)) {
+       if (2 < argc) {
                error("too many parameters");
-               usage_with_options(git_notes_usage, options);
+               usage_with_options(usage, options);
        }
 
+       if (msg.given && edit)
+               fprintf(stderr, "The -m/-F/-c/-C options have been deprecated "
+                       "for the 'edit' subcommand.\n"
+                       "Please use 'git notes add -f -m/-F/-c/-C' instead.\n");
+
+       object_ref = 1 < argc ? argv[1] : "HEAD";
+
        if (get_sha1(object_ref, object))
                die("Failed to resolve '%s' as a valid ref.", object_ref);
 
-       init_notes(NULL, NULL, NULL, 0);
-       t = &default_notes_tree;
+       t = init_notes_check(argv[0]);
+       note = get_note(t, object);
 
-       if (prefixcmp(t->ref, "refs/notes/"))
-               die("Refusing to %s notes in %s (outside of refs/notes/)",
-                   argv[0], t->ref);
+       create_note(object, &msg, !edit, note, new_note);
 
-       note = get_note(t, object);
+       if (is_null_sha1(new_note))
+               remove_note(t, object);
+       else if (add_note(t, object, new_note, combine_notes_overwrite))
+               die("BUG: combine_notes_overwrite failed");
+
+       snprintf(logmsg, sizeof(logmsg), "Notes %s by 'git notes %s'",
+                is_null_sha1(new_note) ? "removed" : "added", argv[0]);
+       commit_notes(t, logmsg);
+       free_notes(t);
+       strbuf_release(&(msg.buf));
+       return 0;
+}
+
+static int show(int argc, const char **argv, const char *prefix)
+{
+       const char *object_ref;
+       struct notes_tree *t;
+       unsigned char object[20];
+       const unsigned char *note;
+       int retval;
+       struct option options[] = {
+               OPT_END()
+       };
 
-       /* list command */
+       argc = parse_options(argc, argv, prefix, options, git_notes_show_usage,
+                            0);
 
-       if (list) {
-               if (given_object) {
-                       if (note) {
-                               puts(sha1_to_hex(note));
-                               goto end;
-                       }
-               } else {
-                       retval = for_each_note(t, 0, list_each_note, NULL);
-                       goto end;
-               }
+       if (1 < argc) {
+               error("too many parameters");
+               usage_with_options(git_notes_show_usage, options);
        }
 
-       /* show command */
+       object_ref = argc ? argv[0] : "HEAD";
+
+       if (get_sha1(object_ref, object))
+               die("Failed to resolve '%s' as a valid ref.", object_ref);
+
+       t = init_notes_check("show");
+       note = get_note(t, object);
 
-       if ((list || show) && !note) {
-               error("No note found for object %s.", sha1_to_hex(object));
-               retval = 1;
-               goto end;
-       } else if (show) {
+       if (!note)
+               retval = error("No note found for object %s.",
+                              sha1_to_hex(object));
+       else {
                const char *show_args[3] = {"show", sha1_to_hex(note), NULL};
                retval = execv_git_cmd(show_args);
-               goto end;
        }
+       free_notes(t);
+       return retval;
+}
 
-       /* add/append/edit/remove/prune command */
+static int merge_abort(struct notes_merge_options *o)
+{
+       int ret = 0;
+
+       /*
+        * Remove .git/NOTES_MERGE_PARTIAL and .git/NOTES_MERGE_REF, and call
+        * notes_merge_abort() to remove .git/NOTES_MERGE_WORKTREE.
+        */
+
+       if (delete_ref("NOTES_MERGE_PARTIAL", NULL, 0))
+               ret += error("Failed to delete ref NOTES_MERGE_PARTIAL");
+       if (delete_ref("NOTES_MERGE_REF", NULL, REF_NODEREF))
+               ret += error("Failed to delete ref NOTES_MERGE_REF");
+       if (notes_merge_abort(o))
+               ret += error("Failed to remove 'git notes merge' worktree");
+       return ret;
+}
 
-       if ((add || copy) && note) {
-               if (!force) {
-                       error("Cannot %s notes. Found existing notes for object"
-                             " %s. Use '-f' to overwrite existing notes",
-                             argv[0], sha1_to_hex(object));
-                       retval = 1;
-                       goto end;
-               }
-               fprintf(stderr, "Overwriting existing notes for object %s\n",
-                       sha1_to_hex(object));
+static int merge_commit(struct notes_merge_options *o)
+{
+       struct strbuf msg = STRBUF_INIT;
+       unsigned char sha1[20], parent_sha1[20];
+       struct notes_tree *t;
+       struct commit *partial;
+       struct pretty_print_context pretty_ctx;
+
+       /*
+        * Read partial merge result from .git/NOTES_MERGE_PARTIAL,
+        * and target notes ref from .git/NOTES_MERGE_REF.
+        */
+
+       if (get_sha1("NOTES_MERGE_PARTIAL", sha1))
+               die("Failed to read ref NOTES_MERGE_PARTIAL");
+       else if (!(partial = lookup_commit_reference(sha1)))
+               die("Could not find commit from NOTES_MERGE_PARTIAL.");
+       else if (parse_commit(partial))
+               die("Could not parse commit from NOTES_MERGE_PARTIAL.");
+
+       if (partial->parents)
+               hashcpy(parent_sha1, partial->parents->item->object.sha1);
+       else
+               hashclr(parent_sha1);
+
+       t = xcalloc(1, sizeof(struct notes_tree));
+       init_notes(t, "NOTES_MERGE_PARTIAL", combine_notes_overwrite, 0);
+
+       o->local_ref = resolve_ref("NOTES_MERGE_REF", sha1, 0, 0);
+       if (!o->local_ref)
+               die("Failed to resolve NOTES_MERGE_REF");
+
+       if (notes_merge_commit(o, t, partial, sha1))
+               die("Failed to finalize notes merge");
+
+       /* Reuse existing commit message in reflog message */
+       memset(&pretty_ctx, 0, sizeof(pretty_ctx));
+       format_commit_message(partial, "%s", &msg, &pretty_ctx);
+       strbuf_trim(&msg);
+       strbuf_insert(&msg, 0, "notes: ", 7);
+       update_ref(msg.buf, o->local_ref, sha1,
+                  is_null_sha1(parent_sha1) ? NULL : parent_sha1,
+                  0, DIE_ON_ERR);
+
+       free_notes(t);
+       strbuf_release(&msg);
+       return merge_abort(o);
+}
+
+static int merge(int argc, const char **argv, const char *prefix)
+{
+       struct strbuf remote_ref = STRBUF_INIT, msg = STRBUF_INIT;
+       unsigned char result_sha1[20];
+       struct notes_tree *t;
+       struct notes_merge_options o;
+       int do_merge = 0, do_commit = 0, do_abort = 0;
+       int verbosity = 0, result;
+       const char *strategy = NULL;
+       struct option options[] = {
+               OPT_GROUP("General options"),
+               OPT__VERBOSITY(&verbosity),
+               OPT_GROUP("Merge options"),
+               OPT_STRING('s', "strategy", &strategy, "strategy",
+                          "resolve notes conflicts using the given strategy "
+                          "(manual/ours/theirs/union/cat_sort_uniq)"),
+               OPT_GROUP("Committing unmerged notes"),
+               { OPTION_BOOLEAN, 0, "commit", &do_commit, NULL,
+                       "finalize notes merge by committing unmerged notes",
+                       PARSE_OPT_NOARG | PARSE_OPT_NONEG },
+               OPT_GROUP("Aborting notes merge resolution"),
+               { OPTION_BOOLEAN, 0, "abort", &do_abort, NULL,
+                       "abort notes merge",
+                       PARSE_OPT_NOARG | PARSE_OPT_NONEG },
+               OPT_END()
+       };
+
+       argc = parse_options(argc, argv, prefix, options,
+                            git_notes_merge_usage, 0);
+
+       if (strategy || do_commit + do_abort == 0)
+               do_merge = 1;
+       if (do_merge + do_commit + do_abort != 1) {
+               error("cannot mix --commit, --abort or -s/--strategy");
+               usage_with_options(git_notes_merge_usage, options);
        }
 
-       if (remove) {
-               msg.given = 1;
-               msg.use_editor = 0;
-               strbuf_reset(&(msg.buf));
+       if (do_merge && argc != 1) {
+               error("Must specify a notes ref to merge");
+               usage_with_options(git_notes_merge_usage, options);
+       } else if (!do_merge && argc) {
+               error("too many parameters");
+               usage_with_options(git_notes_merge_usage, options);
        }
 
-       if (prune) {
-               hashclr(new_note);
-               prune_notes(t);
-               goto commit;
-       } else if (copy) {
-               const unsigned char *from_note = get_note(t, from_obj);
-               if (!from_note) {
-                       error("Missing notes on source object %s. Cannot copy.",
-                             sha1_to_hex(from_obj));
-                       retval = 1;
-                       goto end;
+       init_notes_merge_options(&o);
+       o.verbosity = verbosity + NOTES_MERGE_VERBOSITY_DEFAULT;
+
+       if (do_abort)
+               return merge_abort(&o);
+       if (do_commit)
+               return merge_commit(&o);
+
+       o.local_ref = default_notes_ref();
+       strbuf_addstr(&remote_ref, argv[0]);
+       expand_notes_ref(&remote_ref);
+       o.remote_ref = remote_ref.buf;
+
+       if (strategy) {
+               if (!strcmp(strategy, "manual"))
+                       o.strategy = NOTES_MERGE_RESOLVE_MANUAL;
+               else if (!strcmp(strategy, "ours"))
+                       o.strategy = NOTES_MERGE_RESOLVE_OURS;
+               else if (!strcmp(strategy, "theirs"))
+                       o.strategy = NOTES_MERGE_RESOLVE_THEIRS;
+               else if (!strcmp(strategy, "union"))
+                       o.strategy = NOTES_MERGE_RESOLVE_UNION;
+               else if (!strcmp(strategy, "cat_sort_uniq"))
+                       o.strategy = NOTES_MERGE_RESOLVE_CAT_SORT_UNIQ;
+               else {
+                       error("Unknown -s/--strategy: %s", strategy);
+                       usage_with_options(git_notes_merge_usage, options);
                }
-               hashcpy(new_note, from_note);
-       } else
-               create_note(object, &msg, append, note, new_note);
+       }
 
-       if (is_null_sha1(new_note))
-               remove_note(t, object);
-       else
-               add_note(t, object, new_note, combine_notes_overwrite);
+       t = init_notes_check("merge");
+
+       strbuf_addf(&msg, "notes: Merged notes from %s into %s",
+                   remote_ref.buf, default_notes_ref());
+       strbuf_add(&(o.commit_msg), msg.buf + 7, msg.len - 7); /* skip "notes: " */
+
+       result = notes_merge(&o, t, result_sha1);
+
+       if (result >= 0) /* Merge resulted (trivially) in result_sha1 */
+               /* Update default notes ref with new commit */
+               update_ref(msg.buf, default_notes_ref(), result_sha1, NULL,
+                          0, DIE_ON_ERR);
+       else { /* Merge has unresolved conflicts */
+               /* Update .git/NOTES_MERGE_PARTIAL with partial merge result */
+               update_ref(msg.buf, "NOTES_MERGE_PARTIAL", result_sha1, NULL,
+                          0, DIE_ON_ERR);
+               /* Store ref-to-be-updated into .git/NOTES_MERGE_REF */
+               if (create_symref("NOTES_MERGE_REF", default_notes_ref(), NULL))
+                       die("Failed to store link to current notes ref (%s)",
+                           default_notes_ref());
+               printf("Automatic notes merge failed. Fix conflicts in %s and "
+                      "commit the result with 'git notes merge --commit', or "
+                      "abort the merge with 'git notes merge --abort'.\n",
+                      git_path(NOTES_MERGE_WORKTREE));
+       }
 
-commit:
-       snprintf(logmsg, sizeof(logmsg), "Notes %s by 'git notes %s'",
-                is_null_sha1(new_note) ? "removed" : "added", argv[0]);
-       commit_notes(t, logmsg);
+       free_notes(t);
+       strbuf_release(&remote_ref);
+       strbuf_release(&msg);
+       return result < 0; /* return non-zero on conflicts */
+}
+
+static int remove_cmd(int argc, const char **argv, const char *prefix)
+{
+       struct option options[] = {
+               OPT_END()
+       };
+       const char *object_ref;
+       struct notes_tree *t;
+       unsigned char object[20];
+       int retval;
+
+       argc = parse_options(argc, argv, prefix, options,
+                            git_notes_remove_usage, 0);
+
+       if (1 < argc) {
+               error("too many parameters");
+               usage_with_options(git_notes_remove_usage, options);
+       }
+
+       object_ref = argc ? argv[0] : "HEAD";
+
+       if (get_sha1(object_ref, object))
+               die("Failed to resolve '%s' as a valid ref.", object_ref);
+
+       t = init_notes_check("remove");
+
+       retval = remove_note(t, object);
+       if (retval)
+               fprintf(stderr, "Object %s has no note\n", sha1_to_hex(object));
+       else {
+               fprintf(stderr, "Removing note for object %s\n",
+                       sha1_to_hex(object));
 
-end:
+               commit_notes(t, "Notes removed by 'git notes remove'");
+       }
        free_notes(t);
-       strbuf_release(&(msg.buf));
        return retval;
 }
+
+static int prune(int argc, const char **argv, const char *prefix)
+{
+       struct notes_tree *t;
+       int show_only = 0, verbose = 0;
+       struct option options[] = {
+               OPT__DRY_RUN(&show_only, "do not remove, show only"),
+               OPT__VERBOSE(&verbose, "report pruned notes"),
+               OPT_END()
+       };
+
+       argc = parse_options(argc, argv, prefix, options, git_notes_prune_usage,
+                            0);
+
+       if (argc) {
+               error("too many parameters");
+               usage_with_options(git_notes_prune_usage, options);
+       }
+
+       t = init_notes_check("prune");
+
+       prune_notes(t, (verbose ? NOTES_PRUNE_VERBOSE : 0) |
+               (show_only ? NOTES_PRUNE_VERBOSE|NOTES_PRUNE_DRYRUN : 0) );
+       if (!show_only)
+               commit_notes(t, "Notes removed by 'git notes prune'");
+       free_notes(t);
+       return 0;
+}
+
+static int get_ref(int argc, const char **argv, const char *prefix)
+{
+       struct option options[] = { OPT_END() };
+       argc = parse_options(argc, argv, prefix, options,
+                            git_notes_get_ref_usage, 0);
+
+       if (argc) {
+               error("too many parameters");
+               usage_with_options(git_notes_get_ref_usage, options);
+       }
+
+       puts(default_notes_ref());
+       return 0;
+}
+
+int cmd_notes(int argc, const char **argv, const char *prefix)
+{
+       int result;
+       const char *override_notes_ref = NULL;
+       struct option options[] = {
+               OPT_STRING(0, "ref", &override_notes_ref, "notes_ref",
+                          "use notes from <notes_ref>"),
+               OPT_END()
+       };
+
+       git_config(git_default_config, NULL);
+       argc = parse_options(argc, argv, prefix, options, git_notes_usage,
+                            PARSE_OPT_STOP_AT_NON_OPTION);
+
+       if (override_notes_ref) {
+               struct strbuf sb = STRBUF_INIT;
+               strbuf_addstr(&sb, override_notes_ref);
+               expand_notes_ref(&sb);
+               setenv("GIT_NOTES_REF", sb.buf, 1);
+               strbuf_release(&sb);
+       }
+
+       if (argc < 1 || !strcmp(argv[0], "list"))
+               result = list(argc, argv, prefix);
+       else if (!strcmp(argv[0], "add"))
+               result = add(argc, argv, prefix);
+       else if (!strcmp(argv[0], "copy"))
+               result = copy(argc, argv, prefix);
+       else if (!strcmp(argv[0], "append") || !strcmp(argv[0], "edit"))
+               result = append_edit(argc, argv, prefix);
+       else if (!strcmp(argv[0], "show"))
+               result = show(argc, argv, prefix);
+       else if (!strcmp(argv[0], "merge"))
+               result = merge(argc, argv, prefix);
+       else if (!strcmp(argv[0], "remove"))
+               result = remove_cmd(argc, argv, prefix);
+       else if (!strcmp(argv[0], "prune"))
+               result = prune(argc, argv, prefix);
+       else if (!strcmp(argv[0], "get-ref"))
+               result = get_ref(argc, argv, prefix);
+       else {
+               result = error("Unknown subcommand: %s", argv[0]);
+               usage_with_options(git_notes_usage, options);
+       }
+
+       return result ? 1 : 0;
+}