Uploaded file store/storeAs fails when uploaded file is empty

[mgkprod]

• Laravel Version: 5.7.16
• PHP Version: 7.2.0 (Windows)

Description:

Using store on an uploaded file fails when you push an empty file (created with touch for example), even with name.extension in the client file name.

$request->file('my_file')->store('public/uploads');

Exception returned :

fopen([...]\storage\app\public/uploads/UBNhJUhG2R2NUc7aLzMcD12bVVPqc1naopTbShv1.): failed to open stream: Permission denied

Digging down, the exception is thrown because of the trailing dot returned by the hashName function, when $this->guessExtension() is null.

Credits to @destinais for the unexpected discovery.

Steps To Reproduce:

1. Upload an empty file
2. Use the store/storeAs method
3. See the returned exception