Server resource packs are saved with a wrong filename.

When I log in to a server that provides a resource pack, Minecraft downloads it for me. It works OK, but the filename it's saved to is wrong. Also, the '.' is missing, so Windows doesn't immediately recognise it as a ZIP file.

What I expected to happen was...:
The resource pack be saved to server-resource-packs/Andrio's world.zip (or Andrio%27s%20world.zip).

What actually happened was...:
The resource pack was saved to server-resource-packs/Andrio27s20worldzip.

Steps to Reproduce:
1. Connect to a server which provides a resource pack.
2. Accept the resource pack to download it.
3. Explore the server-resource-packs folder.