1.20.0 - video rotation and runahead bug

Description

It seems there is a problem with the video_rotation parameter being set to something other than 0 and also run ahead being enabled, so it doesn't rotate correctly.

You can change the rotation again from the menu and then it rotates correctly, but this prevents you from being able to control the rotation with appendconfig or just having the parameter enabled when you launch the game.

Tested with the latest retroarch versions (windows x64) for fbneo and mame cores and they all have the same problem using default retroarch.cfg without changing anything else but those two options.

Expected behavior

The rotation should occur correctly regardless of the value of run_ahead, in fact it is possible to use both options if the rotation value is changed from retroarch menu.

Steps to reproduce the bug

1. restore default retroarch.cfg
2. edit and change video_rotation option to 270º p.e (video_rotation="3") and enable run_ahead (run_ahead_enabled="true")
3. launch retroarch and check rotation, then you can change the rotation from settings/video/output/video rotation option or run_ahead_enabled to "false" in config file and now is done correctly.

Version/Commit

1.20.0

Bisect Results

tested with same result from 1.15.0 to 1.20.0

Check in the nightly version

Yes, this is reproduced in the nightly build

Platform & operating system

Windows 10 x64

Affected Cores

fbneo,mame

Environment information

Video driver: d3d11,vulkan,glcore

Reproduce with the default retroarch.cfg on Windows using video_rotation="3" and run_ahead_enabled="true", checking fbneo and mame with the listed video drivers. Trace the startup/configuration path for these options and compare it with changing Video Rotation or run_ahead_enabled from the menu; done means rotation works correctly when both options are enabled at launch.