Fix NPE on inner port

Signed-off-by: Chris Lavin <[email protected]>

Author: clavin-xlnx

src/com/xilinx/rapidwright/gui/SchematicScene.java

@@ -621,7 +621,9 @@ private void createExpandedCellInnerPorts(EDIFHierCellInst inst) {
                 // Map the inner port inst to the outer one so nets are aligned
                 if (outerElkPort != null) {
                     EDIFPortInst innerPortInst = port.getInternalPortInstFromIndex(i);
-                    portInstMap.put(inst.getPortInst(innerPortInst.getName()), outerElkPort);
+                    if (innerPortInst != null) {
+                        portInstMap.put(inst.getPortInst(innerPortInst.getName()), outerElkPort);
+                    }
                 }
             }
         }