X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=builtin-revert.c;h=365b330f9e1f2989683611077d260fa49abcb889;hb=5d3d1cacc139194672a6a184509bb620a19b2497;hp=2ea766b5bfc1375a2ff03664ffb55fa558b11da0;hpb=f81037947c518703cefee2ada5a5d7f724191bc6;p=git.git

diff --git a/builtin-revert.c b/builtin-revert.c
index 2ea766b5b..365b330f9 100644
--- 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;
@@ -244,7 +246,9 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 	if (no_commit) {
 		/*
 		 * We do not intend to commit immediately.  We just want to
-		 * merge the differences in.
+		 * merge the differences in, so let's compute the tree
+		 * that represents the "current" state for merge-recursive
+		 * to work on.
 		 */
 		if (write_tree(head, 0, NULL))
 			die ("Your index file is unmerged.");
@@ -254,15 +258,36 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 		if (get_sha1("HEAD", head))
 			die ("You do not have a valid HEAD");
 		wt_status_prepare(&s);
-		if (s.commitable || s.workdir_dirty)
+		if (s.commitable)
 			die ("Dirty index: cannot %s", me);
 		discard_cache();
 	}
 
 	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 +316,14 @@ 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 +366,7 @@ 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 "