Change 991038 had a related patch set uploaded (by Fomafix; author: Fomafix):

[mediawiki/extensions/CategoryTree@master] Stay on mode=categories after the first submit with all namespaces

https://gerrit.wikimedia.org/r/991038

This addresses the bug in the task description.

before:

after:

BUT
it doesn't address this case:

• If I select "categories only" and namespace "Talk"
• Click show tree

Expected: categories only should remain selected.

@Jdlrobson: Is this still a regression?

@Fomafix I'm not sure I understand the question? If this bug is about making sure the form values persist across submissions we should make sure all the input fields persist correctly, right?

The bug description is about a specific bug which was accidental introduced by change rECTRaec8d75570fd: Replace WebRequest::getVal by ::getRawVal or ::getText. This bug gets fixed by https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CategoryTree/+/991038 PS1. But you blocked this change.

The code contains some more strange behaviors with replacements of the filters based on specific namespaces. This is probably not a bug (and no regression), this is a feature.

@Fomafix I'm not comfortable with this code enough to see this as a feature. I don't mean to block the change, so I've removed my review. Feel free to find another reviewer who understands this workflow better! Sorry I can't be more help.