I came across a couple of bugs today in the Thunderbird code that need a fix, and they are both easy fixes for a student looking for contribution. Basically, in DXR I have a C++ parser to create HTML files with markup versions of source code. My parser chokes on 2 files, because someone did a bad thing and put an extra 0x0c (e.g., \f, form-feed) char in there. This causes all sorts of bad things to happen with tools that try and work on the source and expect things like \n or \r\n or whatever.
[dave@scotland dxr]$ find ./mozilla-trees -name '*.h' -o -name '*.cpp' | xargs grep -n '^L'
NOTE: to get that ^L you have to type: CTRL+V CTRL+L. This will take you about 1 minute plus the time to build Thunderbird, file a bug, and submit the patch. Interested? If so, leave a comment here or talk to me on irc/email.