[Vulkan] Integer scaling + overscale produce black screen (in Vulkan mode only)

[bidinou]

Description

Vulkan + Integer scaling + Overscale options produce a black screen while content is running No issue in GL mode

Expected behavior

Picture should be scaled slightly larger than the screen.

Actual behavior

Screen is black (but content is running)

Steps to reproduce the bug

1. Enable integer scaling
2. Enable overscaling (the option just below it)
3. Start a content : if GL output is enabled, it should work ; if Vulkan output is enable, picture should be black

Bisect Results

Already occurred in 3 years old Android build from the Play Store.

Version/Commit

RetroArch 1.17

Environment information

Android 14 Samsung A34

[kp8888]

Same exact thing happens with overscaling in my Arch Linux install for as long as I can remember. Might be a limitation with the vulkan driver itself.

[sonninnos]

Windows is fine.

[Nargash]

I can produce this on Linux as well. One thing to note, this only happens when the scaled resolution is greater than your monitor resolution (if running full screen) or the window resolution (if running in windowed mode). I wonder if this is related to #8771 which seems to also affect Windows?