From ed8e61dc5d4298452d6372a9e7aea5c8cc2ba01a Mon Sep 17 00:00:00 2001
From: Leon Krause <lk@leonkrause.com>
Date: Thu, 30 Aug 2018 02:23:06 +0200
Subject: [PATCH] Fix HTML5 gamepad input

(cherry picked from commit cd7c0f67b9f3497ec420da97c6a29c43c68612c2)
---
 platform/javascript/os_javascript.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/platform/javascript/os_javascript.cpp b/platform/javascript/os_javascript.cpp
index e2dba1f9761..c0434a93213 100644
--- a/platform/javascript/os_javascript.cpp
+++ b/platform/javascript/os_javascript.cpp
@@ -805,8 +805,11 @@ void OS_JavaScript::process_joysticks() {
 	int joy_count = emscripten_get_num_gamepads();
 	for (int i = 0; i < joy_count; i++) {
 		EmscriptenGamepadEvent state;
-		emscripten_get_gamepad_status(i, &state);
-		if (state.connected) {
+		EMSCRIPTEN_RESULT query_result = emscripten_get_gamepad_status(i, &state);
+		// Chromium reserves gamepads slots, so NO_DATA is an expected result.
+		ERR_CONTINUE(query_result != EMSCRIPTEN_RESULT_SUCCESS &&
+				query_result != EMSCRIPTEN_RESULT_NO_DATA);
+		if (query_result == EMSCRIPTEN_RESULT_SUCCESS && state.connected) {
 
 			int num_buttons = MIN(state.numButtons, 18);
 			int num_axes = MIN(state.numAxes, 8);