Before reporting a bug, you should try stripping down your Vim configuration and removing other plugins. The sad truth about VimScript is that it is fraught with incompatibilities waiting to happen. I'm happy to work around them where I can, but it's up to you to isolate the conflict.
Fugitive is particularly prone to regressions due to Git version issues, platform issues, and interactions with other plugins. I end up bisecting a lot more than other projects, and thus I'm especially meticulous here about maintaining a clean, readable, history. Squash and force push any requested changes to a pull request. And if your commit message sucks, I'm not going to accept it. Period.
Beyond that, don't be shy about asking before patching. What takes you hours might take me minutes simply because I have both domain knowledge and a perverse knowledge of VimScript so vast that many would consider it a symptom of mental illness. On the flip side, some ideas I'll reject no matter how good the implementation is. "Send a patch" is an edge case answer in my book.