Date: Tue, 16 Mar 2004 12:40:33 +0000

From: Alan Swanson
Subject: [SDL] [PATCH] Linux joystick evdev axis count fix

The event device configuration under Linux does not check the returned
ioctl value when reading the axis information. This means extra
undefined axes are returned.

Note, in EV_HandleEvents, the default for case EV_ABS is to return any
axis information which is fine as we have already checked for all valid
absolute axes. No new axes should be returned after opening the device.

(Unless, of course, the evdev allows closing and reassigning a new
device while in use and I can't believe that happens.)

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40897

src/joystick/linux/SDL_sysjoystick.c

@@ -594,7 +594,8 @@ static SDL_bool EV_ConfigJoystick(SDL_Joystick *joystick, int fd)
 			if ( test_bit(i, absbit) ) {
 				int values[5];
 
-				ioctl(fd, EVIOCGABS(i), values);
+				if ( ioctl(fd, EVIOCGABS(i), values) < 0 )
+					continue;
 #ifdef DEBUG_INPUT_EVENTS
 				printf("Joystick has absolute axis: %x\n", i);
 				printf("Values = { %d, %d, %d, %d, %d }\n",