I’m definitely feeling better about working on projects with _huge_ codebases like Thunderbird. I’m currently working on a patch to add a “Reopen last tab” button to Thunderbird. I’m finally feeling like I know my way around Thunderbird’s tab management code. I submitted a patch a couple weeks ago and got some feedback, and I’ve done most of what the patch suggested. The only thing left to do before I submit my patch again is to figure out why the UI tests sometimes pass and sometimes fail on my computer (even without my patch applied!) After I get that figured out, I need to write a few more UI tests. After that I’ll be ready to submit my patch again.
My next patch will to create a menu of recently closed tabs, so the user can select from several tabs that they’ve just closed, similar to in Firefox.