Patched to compile.
diff --git a/src/video/emscripten/SDL_emscriptenevents.c b/src/video/emscripten/SDL_emscriptenevents.c
index 5ebd6a9..5fb08a6 100644
--- a/src/video/emscripten/SDL_emscriptenevents.c
+++ b/src/video/emscripten/SDL_emscriptenevents.c
@@ -431,6 +431,7 @@ Emscripten_HandleFocus(int eventType, const EmscriptenFocusEvent *wheelEvent, vo
static EM_BOOL
Emscripten_HandleTouch(int eventType, const EmscriptenTouchEvent *touchEvent, void *userData)
{
+ SDL_WindowData *window_data = (SDL_WindowData *) userData;
int i;
double client_w, client_h;
int preventDefault = 0;