readable.js: implicit _read() call when "lowWaterMark" is greater than 0

readable-lwm.diff

diff --git a/readable.js b/readable.js
index 3e9253a..b10daa8 100644
--- a/readable.js
+++ b/readable.js
@@ -104,6 +104,21 @@ function Readable(options) {
   this.readable = true;
 
   Stream.apply(this);
+
+  if (this._readableState.lowWaterMark != 0) {
+    // we probably need an implicit _read() call. have to nextTick it in
+    // case the _read function gets defined after this Readable gets returned
+    process.nextTick(checkRead(this));
+  }
+}
+
+function checkRead(readable) {
+  var state = readable._readableState;
+  return function() {
+    if (state.length < state.lowWaterMark) {
+      readable.read(0);
+    }
+  };
 }
 
 // backwards compatibility.