fixed #9 - multipart transformations broken

lib/transforms/multipart._js

@@ -5,6 +5,7 @@
 /// `var ez = require("ez-streams")`  
 /// 
 var generic = require('../devices/generic');
+var flows = require('streamline/lib/util/flows');
 
 function parseContentType(contentType) {
 	if (!contentType) throw new Error("content-type missing");
@@ -34,6 +35,7 @@ module.exports = {
 
 		return function(_, reader, writer) {
 			reader = reader.peekable();
+			var handshake = flows.handshake();
 			while (true) {
 				var buf = reader.read(_, 2048);
 				if (!buf || !buf.length) return;
@@ -52,7 +54,10 @@ module.exports = {
 				var read = function(_) {
 						var len = Math.max(boundary.length, 256);
 						var buf = reader.read(_, 32 * len);
-						if (!buf || !buf.length) return;
+						if (!buf || !buf.length) {
+							handshake.notify();
+							return;
+						}
 						// would be nice if Buffer had an indexOf. Would avoid a conversion to string.
 						// I could use node-buffertools but it introduces a dependency on a binary module.
 						var s = buf.toString("binary");
@@ -61,6 +66,7 @@ module.exports = {
 							var j = s.indexOf('\n', boundary.length);
 							if (j < 0) throw new Error("newline missing after boundary");
 							reader.unread(buf.slice(j + 1));
+							handshake.notify();
 							return undefined;
 						} else if (i > 0) {
 							var j = s.lastIndexOf('\n', i);
@@ -75,6 +81,7 @@ module.exports = {
 				var partReader = generic.reader(read);
 				partReader.headers = headers;
 				writer.write(_, partReader);
+				handshake.wait(_);
 			}
 		};
 	},