[lfs] Check if AppData/ProgramData paths exist

[CommandMC]

When a user had EGL sync enabled and then deleted/uninstalled the EGL, we would still try to load manifests from the directories, which lead to just about every feature breaking & a somewhat inconclusive stacktrace.
This PR avoids this issue by not reading manifests/configuration data when the folders don't exist.

Maybe we should also turn off egl sync if this happens?

[StefanLobbenmeier]

There might be a regression for this, not sure. I just tested this on Windows:

C:\Users\Stefan> C:\Users\Stefan\AppData\Local\Programs\heroic\resources\app.asar.unpacked\build\bin\win32\legendary launch 76233c0af0a441c7bd541e7d7ab3cde1 --language en
[Core] INFO: Synced app "76233c0af0a441c7bd541e7d7ab3cde1" is no longer in the EGL manifest list.
[Core] INFO: Game files exist, assuming game is still installed, re-exporting to EGL...
Traceback (most recent call last):
  File "legendary\cli.py", line 3051, in <module>
  File "legendary\cli.py", line 2966, in main
  File "legendary\cli.py", line 564, in launch_game
  File "legendary\core.py", line 560, in get_installed_game
  File "legendary\core.py", line 1816, in egl_sync
  File "legendary\core.py", line 1802, in egl_restore_or_uninstall
  File "legendary\core.py", line 1779, in egl_export
  File "legendary\lfs\egl.py", line 85, in set_manifest
ValueError: EGS ProgramData path does not exist
[4900] Failed to execute script 'cli' due to unhandled exception!

Version seems to be the latest:

C:\Users\Stefan> C:\Users\Stefan\AppData\Local\Programs\heroic\resources\app.asar.unpacked\build\bin\win32\legendary
usage: legendary.exe [-h] [-H] [-v] [-y] [-V] [-J] [-A <seconds>] <command> ...
Legendary v0.20.27 - "Dark Energy (hotfix)"

[StefanLobbenmeier]

Ahh no, sorry - this behaviour was introduced by this PR.

Maybe we should also turn off egl sync if this happens?

I guess this would have been a good idea.

I was able to fix it on my machine by running legendary egl-sync --disable-sync, so hopefully this will help people out in the future.

[PenguinNexus]

Ahh no, sorry - this behaviour was introduced by this PR.

Maybe we should also turn off egl sync if this happens?

I guess this would have been a good idea.

I was able to fix it on my machine by running legendary egl-sync --disable-sync, so hopefully this will help people out in the future.

Thank you so much! Had the same error on Heroic V2.7.1 (latest at time of writing) and this fixed it!