Bitbucket New File allows whitespace after filename (BB-12503)

I created a new file via the bitbucket UI in the source page of a repository.

When i copy/pasted the filename, there was an erroneous space at the end of the filename, ie "filename.txt "

It wasn't obvious, git handled the space, but it broke a bunch of stuff and took me ages to work out what was going on.

I suggest somehow making pre or post whitespace obvious in the New File filename dialog, a warning on save, or stripping it out automatically.