git-rev-parse --parseopt

[git.git] / builtin-revert.c

diff --git a/builtin-revert.c b/builtin-revert.c
index 2ea766b5bfc1375a2ff03664ffb55fa558b11da0..62ab1fa1f484a113f45da96de8cd209a0c5c522e 100644 (file)
--- a/builtin-revert.c
+++ b/builtin-revert.c
@@ -30,7 +30,7 @@ static const char * const cherry_pick_usage[] = {
        NULL
 };
 
-static int edit, no_replay, no_commit, needed_deref;
+static int edit, no_replay, no_commit, needed_deref, mainline;
 static enum { REVERT, CHERRY_PICK } action;
 static struct commit *commit;
 
@@ -50,12 +50,14 @@ static void parse_args(int argc, const char **argv)
                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_INTEGER('m', "mainline", &mainline, "parent number"),
                OPT_END(),
        };
 
        if (parse_options(argc, argv, options, usage_str, 0) != 1)
                usage_with_options(usage_str, options);
        arg = argv[0];
+
        if (get_sha1(arg, sha1))
                die ("Cannot find '%s'", arg);
        commit = (struct commit *)parse_object(sha1);
@@ -226,7 +228,7 @@ static int merge_recursive(const char *base_sha1,
 static int revert_or_cherry_pick(int argc, const char **argv)
 {
        unsigned char head[20];
-       struct commit *base, *next;
+       struct commit *base, *next, *parent;
        int i;
        char *oneline, *reencoded_message = NULL;
        const char *message, *encoding;
@@ -261,8 +263,29 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 
        if (!commit->parents)
                die ("Cannot %s a root commit", me);
-       if (commit->parents->next)
-               die ("Cannot %s a multi-parent commit.", me);
+       if (commit->parents->next) {
+               /* Reverting or cherry-picking a merge commit */
+               int cnt;
+               struct commit_list *p;
+
+               if (!mainline)
+                       die("Commit %s is a merge but no -m option was given.",
+                           sha1_to_hex(commit->object.sha1));
+
+               for (cnt = 1, p = commit->parents;
+                    cnt != mainline && p;
+                    cnt++)
+                       p = p->next;
+               if (cnt != mainline || !p)
+                       die("Commit %s does not have parent %d",
+                           sha1_to_hex(commit->object.sha1), mainline);
+               parent = p->item;
+       } else if (0 < mainline)
+               die("Mainline was specified but commit %s is not a merge.",
+                   sha1_to_hex(commit->object.sha1));
+       else
+               parent = commit->parents->item;
+
        if (!(message = commit->buffer))
                die ("Cannot get commit message for %s",
                                sha1_to_hex(commit->object.sha1));
@@ -291,14 +314,14 @@ static int revert_or_cherry_pick(int argc, const char **argv)
                char *oneline_body = strchr(oneline, ' ');
 
                base = commit;
-               next = commit->parents->item;
+               next = parent;
                add_to_msg("Revert \"");
                add_to_msg(oneline_body + 1);
                add_to_msg("\"\n\nThis reverts commit ");
                add_to_msg(sha1_to_hex(commit->object.sha1));
                add_to_msg(".\n");
        } else {
-               base = commit->parents->item;
+               base = parent;
                next = commit;
                set_author_ident_env(message);
                add_message_to_msg(message);
@@ -341,7 +364,7 @@ static int revert_or_cherry_pick(int argc, const char **argv)
                        die ("Error wrapping up %s", defmsg);
                fprintf(stderr, "Automatic %s failed.  "
                        "After resolving the conflicts,\n"
-                       "mark the corrected paths with 'git-add <paths>'\n"
+                       "mark the corrected paths with 'git add <paths>' "
                        "and commit the result.\n", me);
                if (action == CHERRY_PICK) {
                        fprintf(stderr, "When commiting, use the option "