--- a/src/network/socket/qlocalsocket_win.cpp	Tue Jan 26 12:42:25 2010 +0200
+++ b/src/network/socket/qlocalsocket_win.cpp	Tue Feb 02 00:43:10 2010 +0200
@@ -363,7 +363,8 @@
     Q_D(const QLocalSocket);
     if (state() != ConnectedState)
         return false;
-    return (d->readBuffer.indexOf('\n') != -1 || QIODevice::canReadLine());
+    return (QIODevice::canReadLine()
+            || d->readBuffer.indexOf('\n', d->actualReadBufferSize) != -1);
 }
 
 void QLocalSocket::close()