In a Mercurial repository, I got a differential revision with "Logo A.svg" and "Logo B.svg".
When we try `arc patch D...`, we have the following message:
Command failed with error #255!
HGPLAIN=1 hg import --no-commit -
applying patch from stdin
file logos/2015-refresh/Logo already exists
1 out of 1 hunks FAILED -- saving rejects to file logos/2015-refresh/Logo.rej
abort: patch failed to apply