* refactor msg-sorting a bit

src/mu-msg.c

@@ -598,25 +598,54 @@ mu_msg_contact_foreach (MuMsg *msg, MuMsgContactForeachFunc func,
 }
 
 
+static int
+cmp_str (const char* s1, const char *s2)
+{
+	if (s1 == s2)
+		return 0;
+	else if (!s1)
+		return -1;
+	else if (!s2)
+		return 1;
+	
+	return g_utf8_collate (s1, s2);
+}
+
+
+static int
+cmp_subject (const char* s1, const char *s2)
+{
+	if (s1 == s2)
+		return 0;
+	else if (!s1)
+		return -1;
+	else if (!s2)
+		return 1;
+	
+	return g_utf8_collate (
+		mu_str_subject_normalize (s1),
+		mu_str_subject_normalize (s2));
+}
+
+
 int
 mu_msg_cmp (MuMsg *m1, MuMsg *m2, MuMsgFieldId mfid)
 {
-	GCompareDataFunc func;
-	
 	g_return_val_if_fail (m1, 0);
 	g_return_val_if_fail (m2, 0);
 	g_return_val_if_fail (mu_msg_field_id_is_valid(mfid), 0);
 	
-	func = mu_msg_field_cmp_func (mfid);
-
+	if (mfid == MU_MSG_FIELD_ID_SUBJECT) 
+		return cmp_subject (get_str_field (m1, mfid),
+				    get_str_field (m2, mfid));
+	
 	if (mu_msg_field_is_string (mfid)) 
-		return func (get_str_field (m1, mfid),
-			     get_str_field (m2, mfid), NULL);
-	/* TODO: special-case 64-bit nums */
-	else if (mu_msg_field_is_numeric (mfid)) 
-		return func (GUINT_TO_POINTER((guint)get_num_field(m1, mfid)),
-			     GUINT_TO_POINTER((guint)get_num_field(m2, mfid)),
-			     NULL);
+		return cmp_str (get_str_field (m1, mfid),
+				get_str_field (m2, mfid));
+
+	/* TODO: note, we cast (potentially > MAXINT to int) */
+	if (mu_msg_field_is_numeric (mfid)) 
+		return get_num_field(m1, mfid) - get_num_field(m2, mfid);
 	
 	return 0; /* TODO: handle lists */
 }