2 files changed, 9 insertions, 5 deletions

diff --git a/platform/javascript/engine.js b/platform/javascript/engine.js
index e4839af43..e3a28083a 100644
--- a/platform/javascript/engine.js
+++ b/platform/javascript/engine.js
@@ -161,6 +161,10 @@
 			actualCanvas.style.padding = 0;
 			actualCanvas.style.borderWidth = 0;
 			actualCanvas.style.borderStyle = 'none';
+			// disable right-click context menu
+			actualCanvas.addEventListener('contextmenu', function(ev) {
+				ev.preventDefault();
+			}, false);
 			// until context restoration is implemented
 			actualCanvas.addEventListener('webglcontextlost', function(ev) {
 				alert("WebGL context lost, please reload the page");
diff --git a/platform/javascript/os_javascript.cpp b/platform/javascript/os_javascript.cpp
index 1b5463e40..cb942b6bb 100644
--- a/platform/javascript/os_javascript.cpp
+++ b/platform/javascript/os_javascript.cpp
@@ -167,10 +167,9 @@ static EM_BOOL _mousebutton_callback(int event_type, const EmscriptenMouseEvent
 	int mask = _input->get_mouse_button_mask();
 	int button_flag = 1 << (ev->get_button_index() - 1);
 	if (ev->is_pressed()) {
-		// since the event is consumed, focus manually
-		if (!is_canvas_focused()) {
-			focus_canvas();
-		}
+		// Since the event is consumed, focus manually. The containing iframe,
+		// if used, may not have focus yet, so focus even if already focused.
+		focus_canvas();
 		mask |= button_flag;
 	} else if (mask & button_flag) {
 		mask &= ~button_flag;
@@ -181,7 +180,8 @@ static EM_BOOL _mousebutton_callback(int event_type, const EmscriptenMouseEvent
 	ev->set_button_mask(mask);
 
 	_input->parse_input_event(ev);
-	// prevent selection dragging
+	// Prevent multi-click text selection and wheel-click scrolling anchor.
+	// Context menu is prevented through contextmenu event.
 	return true;
 }