Merge branch 'jc/maint-am-abort-safely'
[gitweb.git] / builtin / revert.c
index 7d68ef714eee5011d82952ca1829016c90827f61..bb6e9e83b756b47dae449064ca7762fe3558fc0e 100644 (file)
@@ -39,29 +39,34 @@ static const char * const cherry_pick_usage[] = {
 static int edit, no_replay, no_commit, mainline, signoff, allow_ff;
 static enum { REVERT, CHERRY_PICK } action;
 static struct commit *commit;
-static const char *commit_name;
+static int commit_argc;
+static const char **commit_argv;
 static int allow_rerere_auto;
 
 static const char *me;
+static const char *strategy;
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
 static char *get_encoding(const char *message);
 
+static const char * const *revert_or_cherry_pick_usage(void)
+{
+       return action == REVERT ? revert_usage : cherry_pick_usage;
+}
+
 static void parse_args(int argc, const char **argv)
 {
-       const char * const * usage_str =
-               action == REVERT ?  revert_usage : cherry_pick_usage;
-       unsigned char sha1[20];
+       const char * const * usage_str = revert_or_cherry_pick_usage();
        int noop;
        struct option options[] = {
                OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
                OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
-               OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
                OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
                OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
                OPT_INTEGER('m', "mainline", &mainline, "parent number"),
                OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
+               OPT_STRING(0, "strategy", &strategy, "strategy", "merge strategy"),
                OPT_END(),
                OPT_END(),
                OPT_END(),
@@ -69,6 +74,7 @@ static void parse_args(int argc, const char **argv)
 
        if (action == CHERRY_PICK) {
                struct option cp_extra[] = {
+                       OPT_BOOLEAN('x', NULL, &no_replay, "append commit name"),
                        OPT_BOOLEAN(0, "ff", &allow_ff, "allow fast-forward"),
                        OPT_END(),
                };
@@ -76,15 +82,13 @@ static void parse_args(int argc, const char **argv)
                        die("program error");
        }
 
-       if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1)
+       commit_argc = parse_options(argc, argv, NULL, options, usage_str,
+                                   PARSE_OPT_KEEP_ARGV0 |
+                                   PARSE_OPT_KEEP_UNKNOWN);
+       if (commit_argc < 2)
                usage_with_options(usage_str, options);
 
-       commit_name = argv[0];
-       if (get_sha1(commit_name, sha1))
-               die ("Cannot find '%s'", commit_name);
-       commit = lookup_commit_reference(sha1);
-       if (!commit)
-               exit(1);
+       commit_argv = argv;
 }
 
 struct commit_message {
@@ -98,9 +102,9 @@ struct commit_message {
 static int get_message(const char *raw_message, struct commit_message *out)
 {
        const char *encoding;
-       const char *p, *abbrev, *eol;
+       const char *abbrev, *subject;
+       int abbrev_len, subject_len;
        char *q;
-       int abbrev_len, oneline_len;
 
        if (!raw_message)
                return -1;
@@ -121,27 +125,17 @@ static int get_message(const char *raw_message, struct commit_message *out)
        abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
        abbrev_len = strlen(abbrev);
 
-       /* Find beginning and end of commit subject. */
-       p = out->message;
-       while (*p && (*p != '\n' || p[1] != '\n'))
-               p++;
-       if (*p) {
-               p += 2;
-               for (eol = p + 1; *eol && *eol != '\n'; eol++)
-                       ; /* do nothing */
-       } else
-               eol = p;
-       oneline_len = eol - p;
+       subject_len = find_commit_subject(out->message, &subject);
 
        out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
-                             strlen("... ") + oneline_len + 1);
+                             strlen("... ") + subject_len + 1);
        q = out->parent_label;
        q = mempcpy(q, "parent of ", strlen("parent of "));
        out->label = q;
        q = mempcpy(q, abbrev, abbrev_len);
        q = mempcpy(q, "... ", strlen("... "));
        out->subject = q;
-       q = mempcpy(q, p, oneline_len);
+       q = mempcpy(q, subject, subject_len);
        *q = '\0';
        return 0;
 }
@@ -174,28 +168,17 @@ static char *get_encoding(const char *message)
        return NULL;
 }
 
-static struct lock_file msg_file;
-static int msg_fd;
-
-static void add_to_msg(const char *string)
-{
-       int len = strlen(string);
-       if (write_in_full(msg_fd, string, len) < 0)
-               die_errno ("Could not write to MERGE_MSG");
-}
-
-static void add_message_to_msg(const char *message)
+static void add_message_to_msg(struct strbuf *msgbuf, const char *message)
 {
        const char *p = message;
        while (*p && (*p != '\n' || p[1] != '\n'))
                p++;
 
        if (!*p)
-               add_to_msg(sha1_to_hex(commit->object.sha1));
+               strbuf_addstr(msgbuf, sha1_to_hex(commit->object.sha1));
 
        p += 2;
-       add_to_msg(p);
-       return;
+       strbuf_addstr(msgbuf, p);
 }
 
 static void set_author_ident_env(const char *message)
@@ -248,27 +231,43 @@ static void set_author_ident_env(const char *message)
                        sha1_to_hex(commit->object.sha1));
 }
 
-static char *help_msg(const char *name)
+static void advise(const char *advice, ...)
 {
-       struct strbuf helpbuf = STRBUF_INIT;
-       char *msg = getenv("GIT_CHERRY_PICK_HELP");
+       va_list params;
 
-       if (msg)
-               return msg;
+       va_start(params, advice);
+       vreportf("hint: ", advice, params);
+       va_end(params);
+}
 
-       strbuf_addstr(&helpbuf, "  After resolving the conflicts,\n"
-               "mark the corrected paths with 'git add <paths>' or 'git rm <paths>'\n"
-               "and commit the result");
+static void print_advice(void)
+{
+       char *msg = getenv("GIT_CHERRY_PICK_HELP");
 
-       if (action == CHERRY_PICK) {
-               strbuf_addf(&helpbuf, " with: \n"
-                       "\n"
-                       "        git commit -c %s\n",
-                       name);
+       if (msg) {
+               fprintf(stderr, "%s\n", msg);
+               return;
        }
-       else
-               strbuf_addch(&helpbuf, '.');
-       return strbuf_detach(&helpbuf, NULL);
+
+       advise("after resolving the conflicts, mark the corrected paths");
+       advise("with 'git add <paths>' or 'git rm <paths>'");
+
+       if (action == CHERRY_PICK)
+               advise("and commit the result with 'git commit -c %s'",
+                      find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
+}
+
+static void write_message(struct strbuf *msgbuf, const char *filename)
+{
+       static struct lock_file msg_file;
+
+       int msg_fd = hold_lock_file_for_update(&msg_file, filename,
+                                              LOCK_DIE_ON_ERROR);
+       if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
+               die_errno("Could not write to %s.", filename);
+       strbuf_release(msgbuf);
+       if (commit_lock_file(&msg_file) < 0)
+               die("Error wrapping up %s", filename);
 }
 
 static struct tree *empty_tree(void)
@@ -305,40 +304,99 @@ static int fast_forward_to(const unsigned char *to, const unsigned char *from)
        return write_ref_sha1(ref_lock, to, "cherry-pick");
 }
 
-static int revert_or_cherry_pick(int argc, const char **argv)
+static int do_recursive_merge(struct commit *base, struct commit *next,
+                             const char *base_label, const char *next_label,
+                             unsigned char *head, struct strbuf *msgbuf)
 {
-       unsigned char head[20];
-       struct commit *base, *next, *parent;
-       const char *base_label, *next_label;
-       int i, index_fd, clean;
-       struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
-       char *defmsg = NULL;
        struct merge_options o;
        struct tree *result, *next_tree, *base_tree, *head_tree;
+       int clean, index_fd;
        static struct lock_file index_lock;
 
-       git_config(git_default_config, NULL);
-       me = action == REVERT ? "revert" : "cherry-pick";
-       setenv(GIT_REFLOG_ACTION, me, 0);
-       parse_args(argc, argv);
+       index_fd = hold_locked_index(&index_lock, 1);
 
-       /* this is copied from the shell script, but it's never triggered... */
-       if (action == REVERT && !no_replay)
-               die("revert is incompatible with replay");
+       read_cache();
 
-       if (allow_ff) {
-               if (signoff)
-                       die("cherry-pick --ff cannot be used with --signoff");
-               if (no_commit)
-                       die("cherry-pick --ff cannot be used with --no-commit");
-               if (no_replay)
-                       die("cherry-pick --ff cannot be used with -x");
-               if (edit)
-                       die("cherry-pick --ff cannot be used with --edit");
+       /*
+        * NEEDSWORK: cherry-picking between branches with
+        * different end-of-line normalization is a pain;
+        * plumb in an option to set o.renormalize?
+        * (or better: arbitrary -X options)
+        */
+       init_merge_options(&o);
+       o.ancestor = base ? base_label : "(empty tree)";
+       o.branch1 = "HEAD";
+       o.branch2 = next ? next_label : "(empty tree)";
+
+       head_tree = parse_tree_indirect(head);
+       next_tree = next ? next->tree : empty_tree();
+       base_tree = base ? base->tree : empty_tree();
+
+       clean = merge_trees(&o,
+                           head_tree,
+                           next_tree, base_tree, &result);
+
+       if (active_cache_changed &&
+           (write_cache(index_fd, active_cache, active_nr) ||
+            commit_locked_index(&index_lock)))
+               die("%s: Unable to write new index file", me);
+       rollback_lock_file(&index_lock);
+
+       if (!clean) {
+               int i;
+               strbuf_addstr(msgbuf, "\nConflicts:\n\n");
+               for (i = 0; i < active_nr;) {
+                       struct cache_entry *ce = active_cache[i++];
+                       if (ce_stage(ce)) {
+                               strbuf_addch(msgbuf, '\t');
+                               strbuf_addstr(msgbuf, ce->name);
+                               strbuf_addch(msgbuf, '\n');
+                               while (i < active_nr && !strcmp(ce->name,
+                                               active_cache[i]->name))
+                                       i++;
+                       }
+               }
        }
 
-       if (read_cache() < 0)
-               die("git %s: failed to read the index", me);
+       return !clean;
+}
+
+/*
+ * If we are cherry-pick, and if the merge did not result in
+ * hand-editing, we will hit this commit and inherit the original
+ * author date and name.
+ * If we are revert, or if our cherry-pick results in a hand merge,
+ * we had better say that the current user is responsible for that.
+ */
+static int run_git_commit(const char *defmsg)
+{
+       /* 6 is max possible length of our args array including NULL */
+       const char *args[6];
+       int i = 0;
+
+       args[i++] = "commit";
+       args[i++] = "-n";
+       if (signoff)
+               args[i++] = "-s";
+       if (!edit) {
+               args[i++] = "-F";
+               args[i++] = defmsg;
+       }
+       args[i] = NULL;
+
+       return run_command_v_opt(args, RUN_GIT_CMD);
+}
+
+static int do_pick_commit(void)
+{
+       unsigned char head[20];
+       struct commit *base, *next, *parent;
+       const char *base_label, *next_label;
+       struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
+       char *defmsg = NULL;
+       struct strbuf msgbuf = STRBUF_INIT;
+       int res;
+
        if (no_commit) {
                /*
                 * We do not intend to commit immediately.  We just want to
@@ -384,7 +442,7 @@ static int revert_or_cherry_pick(int argc, const char **argv)
        else
                parent = commit->parents->item;
 
-       if (allow_ff && !hashcmp(parent->object.sha1, head))
+       if (allow_ff && parent && !hashcmp(parent->object.sha1, head))
                return fast_forward_to(commit->object.sha1, head);
 
        if (parent && parse_commit(parent) < 0)
@@ -403,110 +461,136 @@ static int revert_or_cherry_pick(int argc, const char **argv)
         */
 
        defmsg = git_pathdup("MERGE_MSG");
-       msg_fd = hold_lock_file_for_update(&msg_file, defmsg,
-                                          LOCK_DIE_ON_ERROR);
-
-       index_fd = hold_locked_index(&index_lock, 1);
 
        if (action == REVERT) {
                base = commit;
                base_label = msg.label;
                next = parent;
                next_label = msg.parent_label;
-               add_to_msg("Revert \"");
-               add_to_msg(msg.subject);
-               add_to_msg("\"\n\nThis reverts commit ");
-               add_to_msg(sha1_to_hex(commit->object.sha1));
+               strbuf_addstr(&msgbuf, "Revert \"");
+               strbuf_addstr(&msgbuf, msg.subject);
+               strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
+               strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 
                if (commit->parents->next) {
-                       add_to_msg(", reversing\nchanges made to ");
-                       add_to_msg(sha1_to_hex(parent->object.sha1));
+                       strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
+                       strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
                }
-               add_to_msg(".\n");
+               strbuf_addstr(&msgbuf, ".\n");
        } else {
                base = parent;
                base_label = msg.parent_label;
                next = commit;
                next_label = msg.label;
                set_author_ident_env(msg.message);
-               add_message_to_msg(msg.message);
+               add_message_to_msg(&msgbuf, msg.message);
                if (no_replay) {
-                       add_to_msg("(cherry picked from commit ");
-                       add_to_msg(sha1_to_hex(commit->object.sha1));
-                       add_to_msg(")\n");
+                       strbuf_addstr(&msgbuf, "(cherry picked from commit ");
+                       strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
+                       strbuf_addstr(&msgbuf, ")\n");
                }
        }
 
-       read_cache();
-       init_merge_options(&o);
-       o.ancestor = base ? base_label : "(empty tree)";
-       o.branch1 = "HEAD";
-       o.branch2 = next ? next_label : "(empty tree)";
-
-       head_tree = parse_tree_indirect(head);
-       next_tree = next ? next->tree : empty_tree();
-       base_tree = base ? base->tree : empty_tree();
+       if (!strategy || !strcmp(strategy, "recursive") || action == REVERT) {
+               res = do_recursive_merge(base, next, base_label, next_label,
+                                        head, &msgbuf);
+               write_message(&msgbuf, defmsg);
+       } else {
+               struct commit_list *common = NULL;
+               struct commit_list *remotes = NULL;
 
-       clean = merge_trees(&o,
-                           head_tree,
-                           next_tree, base_tree, &result);
+               write_message(&msgbuf, defmsg);
 
-       if (active_cache_changed &&
-           (write_cache(index_fd, active_cache, active_nr) ||
-            commit_locked_index(&index_lock)))
-               die("%s: Unable to write new index file", me);
-       rollback_lock_file(&index_lock);
+               commit_list_insert(base, &common);
+               commit_list_insert(next, &remotes);
+               res = try_merge_command(strategy, common,
+                                       sha1_to_hex(head), remotes);
+               free_commit_list(common);
+               free_commit_list(remotes);
+       }
 
-       if (!clean) {
-               add_to_msg("\nConflicts:\n\n");
-               for (i = 0; i < active_nr;) {
-                       struct cache_entry *ce = active_cache[i++];
-                       if (ce_stage(ce)) {
-                               add_to_msg("\t");
-                               add_to_msg(ce->name);
-                               add_to_msg("\n");
-                               while (i < active_nr && !strcmp(ce->name,
-                                               active_cache[i]->name))
-                                       i++;
-                       }
-               }
-               if (commit_lock_file(&msg_file) < 0)
-                       die ("Error wrapping up %s", defmsg);
-               fprintf(stderr, "Automatic %s failed.%s\n",
-                       me, help_msg(commit_name));
+       if (res) {
+               error("could not %s %s... %s",
+                     action == REVERT ? "revert" : "apply",
+                     find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
+                     msg.subject);
+               print_advice();
                rerere(allow_rerere_auto);
-               exit(1);
+       } else {
+               if (!no_commit)
+                       res = run_git_commit(defmsg);
        }
-       if (commit_lock_file(&msg_file) < 0)
-               die ("Error wrapping up %s", defmsg);
-       fprintf(stderr, "Finished one %s.\n", me);
 
-       /*
-        *
-        * If we are cherry-pick, and if the merge did not result in
-        * hand-editing, we will hit this commit and inherit the original
-        * author date and name.
-        * If we are revert, or if our cherry-pick results in a hand merge,
-        * we had better say that the current user is responsible for that.
-        */
+       free_message(&msg);
+       free(defmsg);
+
+       return res;
+}
+
+static void prepare_revs(struct rev_info *revs)
+{
+       int argc;
+
+       init_revisions(revs, NULL);
+       revs->no_walk = 1;
+       if (action != REVERT)
+               revs->reverse = 1;
+
+       argc = setup_revisions(commit_argc, commit_argv, revs, NULL);
+       if (argc > 1)
+               usage(*revert_or_cherry_pick_usage());
+
+       if (prepare_revision_walk(revs))
+               die("revision walk setup failed");
+
+       if (!revs->commits)
+               die("empty commit set passed");
+}
+
+static void read_and_refresh_cache(const char *me)
+{
+       static struct lock_file index_lock;
+       int index_fd = hold_locked_index(&index_lock, 0);
+       if (read_index_preload(&the_index, NULL) < 0)
+               die("git %s: failed to read the index", me);
+       refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
+       if (the_index.cache_changed) {
+               if (write_index(&the_index, index_fd) ||
+                   commit_locked_index(&index_lock))
+                       die("git %s: failed to refresh the index", me);
+       }
+       rollback_lock_file(&index_lock);
+}
+
+static int revert_or_cherry_pick(int argc, const char **argv)
+{
+       struct rev_info revs;
 
-       if (!no_commit) {
-               /* 6 is max possible length of our args array including NULL */
-               const char *args[6];
-               int i = 0;
-               args[i++] = "commit";
-               args[i++] = "-n";
+       git_config(git_default_config, NULL);
+       me = action == REVERT ? "revert" : "cherry-pick";
+       setenv(GIT_REFLOG_ACTION, me, 0);
+       parse_args(argc, argv);
+
+       if (allow_ff) {
                if (signoff)
-                       args[i++] = "-s";
-               if (!edit) {
-                       args[i++] = "-F";
-                       args[i++] = defmsg;
-               }
-               args[i] = NULL;
-               return execv_git_cmd(args);
+                       die("cherry-pick --ff cannot be used with --signoff");
+               if (no_commit)
+                       die("cherry-pick --ff cannot be used with --no-commit");
+               if (no_replay)
+                       die("cherry-pick --ff cannot be used with -x");
+               if (edit)
+                       die("cherry-pick --ff cannot be used with --edit");
+       }
+
+       read_and_refresh_cache(me);
+
+       prepare_revs(&revs);
+
+       while ((commit = get_revision(&revs))) {
+               int res = do_pick_commit();
+               if (res)
+                       return res;
        }
-       free_message(&msg);
-       free(defmsg);
 
        return 0;
 }
@@ -515,14 +599,12 @@ int cmd_revert(int argc, const char **argv, const char *prefix)
 {
        if (isatty(0))
                edit = 1;
-       no_replay = 1;
        action = REVERT;
        return revert_or_cherry_pick(argc, argv);
 }
 
 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 {
-       no_replay = 0;
        action = CHERRY_PICK;
        return revert_or_cherry_pick(argc, argv);
 }