--- dovecot-1.0.10/src/plugins/zlib/istream-zlib.c	2008-01-18 23:43:42.844533000 +0000
+++ dovecot-1.0.10/src/plugins/zlib/istream-zlib.c.patched	2008-01-18 20:07:32.537620000 +0000
@@ -56,7 +56,7 @@
 
 	old_size = stream->buffer_size;
 
-	stream->buffer_size = stream->pos + bytes;
+	stream->buffer_size += bytes;
 	if (stream->buffer_size <= I_STREAM_MIN_SIZE)
 		stream->buffer_size = I_STREAM_MIN_SIZE;
 	else {