Description of the Issue

The read-only attribute is not being set correctly

Steps to Reproduce the Issue

1. right click tab
2. choose read-only option

Expected Behavior

Read-only attribute to be set

Actual Behavior

No errors reported but using file explorer it shows that the read-only flag is unset

Debug Information

Notepad++ v7.5.6 (32-bit)
Build time : Mar 19 2018 - 00:26:59
Path : C:\Program Files (x86)\Notepad++\notepad++.exe
Admin mode : OFF
Local Conf mode : OFF
OS : Windows 10 (64-bit)
Plugins : ComparePlugin.dll DSpellCheck.dll mimeTools.dll NppConverter.dll NppExport.dll