sha1_name.c: fix parsing of ":/token" syntax

The parser tried to clean up the object flags it used while finding
commits with matching string, but was not doing a very good job at it.

This caused "checkout -b new ':/token'", which internally tries to parse
':/token' twice as an object name, to fail when the commit in question
was reachable from only one ref.

The mask bits given to pop_most_recent_commit(&list, MASK) means "I have
already been on the list to be processed, so please do not place me again
even if I am found to be a parent of some other commit on the list."  So
mark them when we add them to the list at the beginning.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

sha1_name.c

@@ -659,6 +659,16 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1)
 	return get_short_sha1(name, len, sha1, 0);
 }
 
+/*
+ * This interprets names like ':/Initial revision of "git"' by searching
+ * through history and returning the first commit whose message starts
+ * with the given string.
+ *
+ * For future extension, ':/!' is reserved. If you want to match a message
+ * beginning with a '!', you have to repeat the exclamation mark.
+ */
+#define ONELINE_SEEN (1u<<20)
+
 static int handle_one_ref(const char *path,
 		const unsigned char *sha1, int flag, void *cb_data)
 {
@@ -674,19 +684,10 @@ static int handle_one_ref(const char *path,
 	if (object->type != OBJ_COMMIT)
 		return 0;
 	insert_by_date((struct commit *)object, list);
+	object->flags |= ONELINE_SEEN;
 	return 0;
 }
 
-/*
- * This interprets names like ':/Initial revision of "git"' by searching
- * through history and returning the first commit whose message starts
- * with the given string.
- *
- * For future extension, ':/!' is reserved. If you want to match a message
- * beginning with a '!', you have to repeat the exclamation mark.
- */
-
-#define ONELINE_SEEN (1u<<20)
 static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
 {
 	struct commit_list *list = NULL, *backup = NULL, *l;