When code relies on non-blocking operation getIn().ready() is providing wrong results.

This happens when IO is reused:
1) output does not contain any line from previous operation
2) getOut().reset() is called
3) because reuse() on NbIO.IOReader is not called getIn().ready() will report false forever (even if there is input
available)

One possible solution would be to change NbIO.IOReader.ready() symmetrically to its read methods:

         public boolean ready() throws IOException {        
             synchronized (lock) {
-                return !inputClosed && buffer().length() > 0;
+                if (inputClosed) {
+                    reuse();
+                    return false;
+                }
+                return buffer().length() > 0;
             }
         }

Other possible solution would be to fix NbWriter().reset() method to not to rely on ((OutWriter) out).isEmpty() in order
to perform real reset.