Patch against trunk
Goto for example https://en.wikipedia.org/wiki/Special:AllMessages. Next to "Filter by customisation state" no radiobutton is checked. Choose 'modified' or 'unmodified' and click go: again no radiobutton is checked. Clicking go again defaults to showing all messages instead of the selected filter.
This happens in 1.18 and 1.19.
Its because class AllmessagesTablePager uses $this->filter to set the radiobuttons instead of $this->custom.
Version: 1.20.x
Severity: normal
Attached: