3 files changed, 26 insertions, 9 deletions

diff --git a/platform/javascript/engine.js b/platform/javascript/engine.js
index e4839af433..c3ef5bbbb5 100644
--- a/platform/javascript/engine.js
+++ b/platform/javascript/engine.js
@@ -10,6 +10,7 @@
 	var DOWNLOAD_ATTEMPTS_MAX = 4;
 
 	var basePath = null;
+	var wasmFilenameExtensionOverride = null;
 	var engineLoadPromise = null;
 
 	var loadingFiles = {};
@@ -129,13 +130,17 @@
 		this.startGame = function(mainPack) {
 
 			executableName = getBaseName(mainPack);
+			var mainArgs = [];
+			if (!getPathLeaf(mainPack).endsWith('.pck')) {
+				mainArgs = ['--main-pack', getPathLeaf(mainPack)];
+			}
 			return Promise.all([
 				// Load from directory,
 				this.init(getBasePath(mainPack)),
 				// ...but write to root where the engine expects it.
 				this.preloadFile(mainPack, getPathLeaf(mainPack))
 			]).then(
-				Function.prototype.apply.bind(synchronousStart, this, [])
+				Function.prototype.apply.bind(synchronousStart, this, mainArgs)
 			);
 		};
 
@@ -161,6 +166,10 @@
 			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");
@@ -299,6 +308,14 @@
 		return !!testContext;
 	};
 
+	Engine.setWebAssemblyFilenameExtension = function(override) {
+
+		if (String(override).length === 0) {
+			throw new Error('Invalid WebAssembly filename extension override');
+		}
+		wasmFilenameExtensionOverride = String(override);
+	}
+
 	Engine.load = function(newBasePath) {
 
 		if (newBasePath !== undefined) basePath = getBasePath(newBasePath);
@@ -306,7 +323,7 @@
 			if (typeof WebAssembly !== 'object')
 				return Promise.reject(new Error("Browser doesn't support WebAssembly"));
 			// TODO cache/retrieve module to/from idb
-			engineLoadPromise = loadPromise(basePath + '.wasm').then(function(xhr) {
+			engineLoadPromise = loadPromise(basePath + '.' + (wasmFilenameExtensionOverride || 'wasm')).then(function(xhr) {
 				return xhr.response;
 			});
 			engineLoadPromise = engineLoadPromise.catch(function(err) {
diff --git a/platform/javascript/export/export.cpp b/platform/javascript/export/export.cpp
index d81aa25c32..9591850662 100644
--- a/platform/javascript/export/export.cpp
+++ b/platform/javascript/export/export.cpp
@@ -117,7 +117,7 @@ void EditorExportPlatformJavaScript::get_export_options(List<ExportOption> *r_op
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "texture_format/s3tc"), true));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "texture_format/etc"), false));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "texture_format/etc2"), true));
-	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "html/custom_html_shell", PROPERTY_HINT_GLOBAL_FILE, "html"), ""));
+	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "html/custom_html_shell", PROPERTY_HINT_FILE, "html"), ""));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "html/head_include", PROPERTY_HINT_MULTILINE_TEXT), ""));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "custom_template/release", PROPERTY_HINT_GLOBAL_FILE, "zip"), ""));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "custom_template/debug", PROPERTY_HINT_GLOBAL_FILE, "zip"), ""));
diff --git a/platform/javascript/os_javascript.cpp b/platform/javascript/os_javascript.cpp
index 1b5463e40d..6c6e4d2d1c 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;
 }
 
@@ -204,7 +204,7 @@ static EM_BOOL _mousemove_callback(int event_type, const EmscriptenMouseEvent *m
 	ev->set_position(pos);
 	ev->set_global_position(ev->get_position());
 
-	ev->set_relative(ev->get_position() - _input->get_mouse_position());
+	ev->set_relative(Vector2(mouse_event->movementX, mouse_event->movementY));
 	_input->set_mouse_position(ev->get_position());
 	ev->set_speed(_input->get_last_mouse_speed());