ID 147984 - Write: file_type doesn't automatically change if there's a Read node in error in the script

Problem summary
The built-in callback in Write nodes that sets the file type automatically when typing a file path in the file knob, stops functioning if there is an errored node upstream in the script.

Customer reported version
nuke.11.1v4

Customer reported platform
Linux - CentOS7

Steps to reproduce

1.   Create a Write knob

2.   In the Write node's file knob, type the following: 'test.jpg'.

4.  Create a Read node. Point it's file knob to a non-existent path (for example '/imgoingtoerror')

5.  View the Read in the Viewer window.

6.  In the Write node, rename the file knob to 'test.jpg'. 

Result:  The file_type knob doesn't change to jpg, the node layout stays the same.

Workaround
Alter any nodes with Errors above the Write node by disabling/deleting/fixing the node.

Reproduced by support

This bug has been reproduced in:
Nuke11.1v4 - Windows 7 - Mac10.12 - CentOS6.9
Nuke11.1v1 - Windows 7 - Mac10.12 - CentOS6.9
Nuke11.0v4 - Windows 7
Nuke11.0v1 - Windows 7 - Mac10.12 - CentOS6.9
Nuke10.5v7 - Windows 7
Nuke10.5v1 - Windows 7 - Mac10.12 - CentOS6.9
Nuke10.0v6 - Windows 7
Nuke10.0v1 - Windows 7 
Nuke9.0v9 - Windows 7
Nuke9.0v1 - Windows 7 - Mac10.12 - CentOS6.9
​Nuke8.0v1 - Windows 7
​Nuke7.0v10 - Windows 7 - Mac10.12 - CentOS6.9

Expected behaviour
The Write node layout functionality should not differ if an error upstream has occurred.

Actual behaviour
The Write node does not alter it's automatic layout, until the error is fixed