I was recently going through some old bug reports for Backdrop CMS and I came across one that I discovered had since been fixed, though the issue was still open. Rather than just closing it, I wanted to post a link to the commit that fixed it (for posterity), so I went looking in GitHub for when the change to the file in question was made...
The file was views_handler_filter_term_node_tid.inc
in the core Taxonomy module, and on line 129 I could see the code that had been a problem but was now fixed:
To see when it was fixed, I did the following: