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Emscripten: Fixed out of range joystick device index after joystick d…

…isconnect.

After disconnecting a joystick the remaining kept their original device index.
This was not correct because the device index must be a number between 0 and
SDL_NumJoysticks(). It was fixed with ideas from SDL's joystick implementation
for Android. Some range checks were removed as the caller already checks them.
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philippwiesemann committed Feb 22, 2015
1 parent 5c43207 commit 8321efba3341c642820aee430e8c1de6eb33be63
Showing with 27 additions and 23 deletions.
  1. +27 −23 src/joystick/emscripten/SDL_sysjoystick.c
@@ -112,7 +112,7 @@ Emscripten_JoyStickConnected(int eventType, const EmscriptenGamepadEvent *gamepa
event.type = SDL_JOYDEVICEADDED;

if (SDL_GetEventState(event.type) == SDL_ENABLE) {
event.jdevice.which = item->index;
event.jdevice.which = numjoysticks - 1;
if ( (SDL_EventOK == NULL) ||
(*SDL_EventOK) (SDL_EventOKParam, &event) ) {
SDL_PushEvent(&event);
@@ -235,6 +235,21 @@ SDL_SYS_JoystickInit(void)
return 0;
}

/* Returns item matching given SDL device index. */
static SDL_joylist_item *
JoystickByDeviceIndex(int device_index)
{
SDL_joylist_item *item = SDL_joylist;

while (0 < device_index) {
--device_index;
item = item->next;
}

return item;
}

/* Returns item matching given HTML gamepad index. */
static SDL_joylist_item *
JoystickByIndex(int index)
{
@@ -265,27 +280,15 @@ void SDL_SYS_JoystickDetect()

/* Function to get the device-dependent name of a joystick */
const char *
SDL_SYS_JoystickNameForDeviceIndex(int index)
SDL_SYS_JoystickNameForDeviceIndex(int device_index)
{
SDL_joylist_item *item = JoystickByIndex(index);
if (item == NULL) {
SDL_SetError("Joystick with index %d not found", index);
return NULL;
}

return item->name;
return JoystickByDeviceIndex(device_index)->name;
}

/* Function to perform the mapping from device index to the instance id for this index */
SDL_JoystickID SDL_SYS_GetInstanceIdOfDeviceIndex(int index)
SDL_JoystickID SDL_SYS_GetInstanceIdOfDeviceIndex(int device_index)
{
SDL_joylist_item *item = JoystickByIndex(index);
if (item == NULL) {
SDL_SetError("Joystick with index %d not found", index);
return 0;
}

return item->device_instance;
return JoystickByDeviceIndex(device_index)->device_instance;
}

/* Function to open a joystick for use.
@@ -294,9 +297,9 @@ SDL_JoystickID SDL_SYS_GetInstanceIdOfDeviceIndex(int index)
It returns 0, or -1 if there is an error.
*/
int
SDL_SYS_JoystickOpen(SDL_Joystick * joystick, int index)
SDL_SYS_JoystickOpen(SDL_Joystick * joystick, int device_index)
{
SDL_joylist_item *item = JoystickByIndex(index);
SDL_joylist_item *item = JoystickByDeviceIndex(device_index);

if (item == NULL ) {
return SDL_SetError("No such device");
@@ -405,18 +408,19 @@ SDL_SYS_JoystickQuit(void)
emscripten_set_gamepaddisconnected_callback(NULL, 0, NULL);
}

SDL_JoystickGUID SDL_SYS_JoystickGetDeviceGUID(int index)
SDL_JoystickGUID
SDL_SYS_JoystickGetDeviceGUID(int device_index)
{
SDL_JoystickGUID guid;
/* the GUID is just the first 16 chars of the name for now */
const char *name = SDL_SYS_JoystickNameForDeviceIndex(index);
const char *name = SDL_SYS_JoystickNameForDeviceIndex(device_index);
SDL_zero(guid);
SDL_memcpy(&guid, name, SDL_min(sizeof(guid), SDL_strlen(name)));
return guid;
}


SDL_JoystickGUID SDL_SYS_JoystickGetGUID(SDL_Joystick * joystick)
SDL_JoystickGUID
SDL_SYS_JoystickGetGUID(SDL_Joystick * joystick)
{
SDL_JoystickGUID guid;
/* the GUID is just the first 16 chars of the name for now */

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