Extension of uploaded file changes due to multiple dots in the filename

What happens:
-------------------------------------------
Let's assume we have a filename with multiple dots at the end of the filename before the extension, like for example foo_bar_e.g..txt
(the e.g. has a dot at the end and the dot of the extension follows). After the fileupload with the upload repository, the file is stored as foo_bar_e.gtxt.

Expected Behaviour:
-------------------------------------------
Filenames with mutliple dots should be uploaded faithfully (as long as the filename is valid, of course).

Remark:
-------------------------------------------
This is especially a problem if the multiple dots are near the extension so that the extension changes. If - for example - an extension changes from .a..pdf to .apdf, then the file is no longer identified as a pdf file and users are left confused.

Replication steps:
a.) Generate a file with multiple dots near the extension (examples: foo..bar.gz or foor_bar.e.g..pdf)
b.) Upload using the upload repository
c.) find the extension changed