ghc -c 7.8 drops last char of file name if -osuf contains a dot

I discovered that if I compile with ghc -c -osuf .something Myfile.hs where Myfile.hs contains TH and thus has to dynamically link in, say, Other.hs, I get the error that

Myfile.hs:1:1:
    cannot find normal object file 'Othe.dyn_o`
    while linking an interpreted expression

So Other was wrongly made into Othe, dropping the last character.

If I don't pass -osuf .something, or have it not have a dot, everything's fine.

The trouble is that -osuf .something worked fine in GHC <= 7.6.

So I believe this is a regression, or at least a very bad error message.

Trac metadata

Trac field	Value
Version	7.8.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Build System
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	aehlig@google.com, nh2
Operating system
Architecture