The KEYBOARD-source veto added in #5439 drops face-button key
events that arrive with both AINPUT_SOURCE_KEYBOARD and
AINPUT_SOURCE_GAMEPAD set on the source bitmask. Confirmed
reproducible on GameSir X2 Type-C and 8BitDo Ultimate Bluetooth,
both reporting source 0x501 on every face-button key event.
This source-bit pattern is general AOSP behaviour since Android
3.2 (commit 6f2fba4 in frameworks/base, Feb 2011): EventHub adds
InputDeviceClass::KEYBOARD to any device whose evdev keyBitmask
claims gamepad buttons (BTN_JOYSTICK..BTN_DIGI), and
KeyboardInputMapper::getEventSource stamps the resulting
KEYBOARD|GAMEPAD source on every outgoing key event.
Use AndroidTranslateGamepadButton(keycode) as the discriminator
instead. Recognised gamepad keycodes route to the gamepad path;
unknown keycodes fall through to the keyboard handler.
Assisted-by: Claude:claude-opus-4-7
4185094359