Steps to reproduce:
1. Set up Perforce workspace and Unity editor integration
2. Create a random file, new C# script is fine
3. In P4V, change the permission of the file to exclusive checking out (-l) but don't change the meta file next to it
4. Now either:
4 a) set up a second workspace, launch a new instance of the Editor, connect it to the same server and check out the file
4 b) Check out the file through P4V
5. Back in the first editor you will see that the file is locked exclusively (remote)
6. Try to Check Out that file
7. Dialog will pop up saying the file couldn't be checked out, but it's attached meta file was checked out successfully
8. Both the check out and locked icons are visible on the overlay of the file

Expected: Since the file is locked exclusively, all corresponding actions to it should not be allowed and there shouldn't be a scenario where it shows as checked out while also remotely and exclusively locked. The meta file should get locked exclusively as well.

Actual: You are able to check out the meta file without the corresponding file with it. It can lead to unexpected behaviour and corrupted data.

Reproduced on: 2018.1.0a3, 2017.3.0b8, 2017.2.0f3, 2017.1.2p2