Playing local files with no extension in name causes data loss

[TomHoward]

A local variable url is used instead of self.url to create a symbolic link. url contains the input filePathURL minus the extension, but if you pass in a file with no extension in the path then url has the same value as filePathURL. A symbolic link from url to filePathURL is then created, meaning we overwrite the input file with a symbolic link to itself causing data loss and we are unable to play as the symbolic link is recursive.

Example

let localFilePath = FileManager.default.urls(
    for: .cachesDirectory,
    in: .userDomainMask
).appendingPathComponent("example-filename-with-no-extension")!

let fileExtension = "FLAC"
let item = CachingPlayerItem(filePathURL: localFilePath, fileExtension: fileExtension)

Filesystem showing issue

$ ls -lahtr /Users/user/Library/Developer/CoreSimulator/Devices/337E1E6C-66A1-42EE-A387-DEC7AA018AE6/data/Containers/Data/Application/BB817909-7D35-4FA0-B16E-8C4C38B5D00D/Library/Caches
total 0
drwxr-xr-x  10 user  user   320B 20 Feb 16:40 ../
lrwxr-xr-x   1 user  user   241B 20 Feb 16:40 example-filename-with-no-extension -> /Users/user/Library/Developer/CoreSimulator/Devices/337E1E6C-66A1-42EE-A387-DEC7AA018AE6/data/Containers/Data/Application/BB817909-7D35-4FA0-B16E-8C4C38B5D00D/Library/Caches/example-filename-with-no-extension