Fix bug 545, by returning early whenever an error occurs when initializing joystick structure

--HG--
branch : SDL-1.2
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/branches/SDL-1.2%402925

src/joystick/SDL_joystick.c

@@ -112,13 +112,17 @@ SDL_Joystick *SDL_JoystickOpen(int device_index)
 
 	/* Create and initialize the joystick */
 	joystick = (SDL_Joystick *)SDL_malloc((sizeof *joystick));
-	if ( joystick != NULL ) {
+	if ( !joystick ) {
+		return(NULL);
+	}
+
 	SDL_memset(joystick, 0, (sizeof *joystick));
 	joystick->index = device_index;
 	if ( SDL_SYS_JoystickOpen(joystick) < 0 ) {
 		SDL_free(joystick);
-			joystick = NULL;
-		} else {
+		return(NULL);
+	}
+
 	if ( joystick->naxes > 0 ) {
 		joystick->axes = (Sint16 *)SDL_malloc
 			(joystick->naxes*sizeof(Sint16));
@@ -141,8 +145,9 @@ SDL_Joystick *SDL_JoystickOpen(int device_index)
 	  || ((joystick->nbuttons > 0) && !joystick->buttons)) {
 		SDL_OutOfMemory();
 		SDL_JoystickClose(joystick);
-				joystick = NULL;
+		return(NULL);
 	}
+
 	if ( joystick->axes ) {
 		SDL_memset(joystick->axes, 0,
 			joystick->naxes*sizeof(Sint16));
@@ -159,17 +164,15 @@ SDL_Joystick *SDL_JoystickOpen(int device_index)
 		SDL_memset(joystick->buttons, 0,
 			joystick->nbuttons*sizeof(Uint8));
 	}
-		}
-	}
-	if ( joystick ) {
+
 	/* Add joystick to list */
 	++joystick->ref_count;
 	SDL_Lock_EventThread();
 	for ( i=0; SDL_joysticks[i]; ++i )
-			/* Skip to next joystick */;
+		/* Skip to next joystick */ ;
 	SDL_joysticks[i] = joystick;
 	SDL_Unlock_EventThread();
-	}
+
 	return(joystick);
 }