@donho Sorry for my late response, but I forgot to answer over the weekend. :D
I’ve tested your fix and the bug is now semi-fixed:
After replacing the Notepad++.exe I’ve started Notepad++ and the bug was still present for Java script files. Then I went into to settings dialog and modified the value for the Java script tab width. After modifying this value everything was fine. This behaviour changed in comparison to the unpatched Notepad++.exe where the tab width keeps wrong after modification in the dialog, so your fix worked at this place.
Unfortunately your fix is not used in a recently started Notepad++. You must go into that dialog and change the setting first, otherwise your fix doesn’t work.
So there should be one place more to fix.