Merge three separate "fetch refs" functions

It really just boils down to one "get_remote_heads()" function, and a
common "struct ref" structure definition.

connect.c

@@ -7,6 +7,41 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 
+/*
+ * Read all the refs from the other end
+ */
+struct ref **get_remote_heads(int in, struct ref **list, int nr_match, char **match)
+{
+	*list = NULL;
+	for (;;) {
+		struct ref *ref;
+		unsigned char old_sha1[20];
+		static char buffer[1000];
+		char *name;
+		int len;
+
+		len = packet_read_line(in, buffer, sizeof(buffer));
+		if (!len)
+			break;
+		if (buffer[len-1] == '\n')
+			buffer[--len] = 0;
+
+		if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
+			die("protocol error: expected sha/ref, got '%s'", buffer);
+		name = buffer + 41;
+		if (nr_match && !path_match(name, nr_match, match))
+			continue;
+		ref = xmalloc(sizeof(*ref) + len - 40);
+		memcpy(ref->old_sha1, old_sha1, 20);
+		memset(ref->new_sha1, 0, 20);
+		memcpy(ref->name, buffer + 41, len - 40);
+		ref->next = NULL;
+		*list = ref;
+		list = &ref->next;
+	}
+	return list;
+}
+
 int get_ack(int fd, unsigned char *result_sha1)
 {
 	static char line[1000];