dump():  Fixed a stupid bug in new code.  It wasn't possible for the bug
to have an effect before protocol 3 is invented, so no test can be
written for this (yet).
diff --git a/Modules/cPickle.c b/Modules/cPickle.c
index 43a8d33..17ccb45 100644
--- a/Modules/cPickle.c
+++ b/Modules/cPickle.c
@@ -2217,7 +2217,7 @@
 		char bytes[2];
 
 		bytes[0] = PROTO;
-		bytes[1] = CURRENT_PROTOCOL_NUMBER;
+		bytes[1] = self->proto;
 		if (self->write_func(self, bytes, 2) < 0)
 			return -1;
 	}