Fixes Space Engineers where triggers do not work currently. That is a regression from before dinput redesign. The game assumes that DIPROP_JOYSTICKID can be used as index for XInputGetState. While that is not the case on Windows for a generic case (and the issue is reproducible on Windows with multiple controllers or controllers not supporting xinput) it is the case at least for simple single controller configurations for controller supporting xinput.
Before dinput redesign DIPROP_JOYSTICKID was (in the most of cases) assigned sequentially for enumerated controllers. That is sort of similar to what happens on Windows (although it is a bit more complicated on Windows). When disconnecting a controller (or even removing it from bluetooth devices, unsinstalling device from Device Manager) Windows may still remember the controller somewhere and adding another one will use the next index; readding previously removed will reuse previously allocated index. However, as seen with dinput tests with Wine test hid driver, removing the driver "frees" the index and it can be reused. Patch 2 implements behaviour similar in important aspect (having sequential indices which will even match xinput in simple cases).
Then, before the redesign dinput supported creating default joystick with GUID_Joystick. This game doesn't depend on that but it looks somewhat connected to indexing and probably worth fixing too. This is a bit not straightforward in a way that even if some controller exists it won't necessarily be created for GUID_Joystick: only the one with DIPROP_JOYSTICKID 0 (which may be absent while higher indices present) will be treated as the default, as test shows.
WRT removal of the test in driver_hid.c, my added test was leading to the same test failure on Win11 and Wine. I also checked that without my added test that failing condition in 'else' is not hit anywhere in pre-existing tests; the condition in 'if' already checked a couple of lines above unconditionally. So I think it was best to just remove that check.