From a9be917e0f35a30c53e79dc9b9e52cc53ed5d4f8 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Wed, 21 Aug 2013 10:31:44 -0700
Subject: [PATCH] Fix SDL xinput code to work at all when xinput has devices at
 high indexes but no device connected at lower index, for instance
 0->disconnected, 1->wireles, 2->wired.  Previously the SDL code assumed the
 indexes were always used up in order which is not true at all and lead to a
 bunch of failure cases where controllers would go unrecognized.

This entire function is kind of a mess and more complicated than needed, but I don't want to refactor it too heavily tonight.  May look at improving how the indexes are assigned more significanly later.  The way it handles not finding a valid "gamepad" type device is also super broken, it leaves in place the xinput bindings but opens the controller with dinput and ends up with completely wrong mappings, not solving that now, but fixing the bug where we'd very frequently not find a controller due to gaps in assigned player numbers should mostly avoid it.
---
 src/joystick/windows/SDL_dxjoystick.c | 92 +++++++++++++++++----------
 1 file changed, 59 insertions(+), 33 deletions(-)

diff --git a/src/joystick/windows/SDL_dxjoystick.c b/src/joystick/windows/SDL_dxjoystick.c
index 0c915a96d..d85ff18a4 100644
--- a/src/joystick/windows/SDL_dxjoystick.c
+++ b/src/joystick/windows/SDL_dxjoystick.c
@@ -1014,40 +1014,66 @@ SDL_SYS_JoystickOpen(SDL_Joystick * joystick, int device_index)
 
         if ( s_bXInputEnabled && XINPUTGETCAPABILITIES )
         {
-            result = XINPUTGETCAPABILITIES( userId, XINPUT_FLAG_GAMEPAD, &capabilities );
-            if ( result == ERROR_SUCCESS )
-            {
-                const SDL_bool bIs14OrLater = (SDL_XInputVersion >= ((1<<16)|4));
-                SDL_bool bIsSupported = SDL_FALSE;
-                /* Current version of XInput mistakenly returns 0 as the Type. Ignore it and ensure the subtype is a gamepad. */
-                bIsSupported = ( capabilities.SubType == XINPUT_DEVSUBTYPE_GAMEPAD );
+			while ( 1 )
+			{
+				result = XINPUTGETCAPABILITIES( userId, XINPUT_FLAG_GAMEPAD, &capabilities );
+				if ( result == ERROR_SUCCESS )
+				{
+					const SDL_bool bIs14OrLater = (SDL_XInputVersion >= ((1<<16)|4));
+					SDL_bool bIsSupported = SDL_FALSE;
+					/* Current version of XInput mistakenly returns 0 as the Type. Ignore it and ensure the subtype is a gamepad. */
+					bIsSupported = ( capabilities.SubType == XINPUT_DEVSUBTYPE_GAMEPAD );
 
-                if ( !bIsSupported )
-                {
-                    joystickdevice->bXInputDevice = SDL_FALSE;
-                }
-                else
-                {
-                    /* valid */
-                    joystick->hwdata->bXInputDevice = SDL_TRUE;
-                    if ((!bIs14OrLater) || (capabilities.Flags & XINPUT_CAPS_FFB_SUPPORTED)) {
-                        joystick->hwdata->bXInputHaptic = SDL_TRUE;
-                    }
-                    SDL_memset( joystick->hwdata->XInputState, 0x0, sizeof(joystick->hwdata->XInputState) );
-                    joystickdevice->XInputUserId = userId;
-                    joystick->hwdata->userid = userId;
-                    joystick->hwdata->currentXInputSlot = 0;
-                    /* The XInput API has a hard coded button/axis mapping, so we just match it */
-                    joystick->naxes = 6;
-                    joystick->nbuttons = 15;
-                    joystick->nballs = 0;
-                    joystick->nhats = 0;
-                }
-            }
-            else
-            {
-                joystickdevice->bXInputDevice = SDL_FALSE;
-            }
+					if ( !bIsSupported )
+					{
+						joystickdevice->bXInputDevice = SDL_FALSE;
+					}
+					else
+					{
+						/* valid */
+						joystick->hwdata->bXInputDevice = SDL_TRUE;
+						if ((!bIs14OrLater) || (capabilities.Flags & XINPUT_CAPS_FFB_SUPPORTED)) {
+							joystick->hwdata->bXInputHaptic = SDL_TRUE;
+						}
+						SDL_memset( joystick->hwdata->XInputState, 0x0, sizeof(joystick->hwdata->XInputState) );
+						joystickdevice->XInputUserId = userId;
+						joystick->hwdata->userid = userId;
+						joystick->hwdata->currentXInputSlot = 0;
+						/* The XInput API has a hard coded button/axis mapping, so we just match it */
+						joystick->naxes = 6;
+						joystick->nbuttons = 15;
+						joystick->nballs = 0;
+						joystick->nhats = 0;
+					}
+					break;
+				}
+				else
+				{
+					if ( userId < XUSER_MAX_COUNT && result == ERROR_DEVICE_NOT_CONNECTED )
+					{
+						/* scan the opened joysticks and pick the next free xinput userid for this one */
+						++userId;
+
+						joysticklist = SYS_Joystick;
+						for( ; joysticklist; joysticklist = joysticklist->pNext)
+						{
+							if ( joysticklist->bXInputDevice && joysticklist->XInputUserId == userId )
+								userId++;
+						}
+
+						if ( userId >= XUSER_MAX_COUNT )
+						{
+							joystickdevice->bXInputDevice = SDL_FALSE;
+							break;
+						}
+					}
+					else
+					{
+						joystickdevice->bXInputDevice = SDL_FALSE;
+						break;
+					}
+				}
+			}
         }
         else
         {