1 files changed, 31 insertions, 7 deletions

diff --git a/platform/javascript/export/export.cpp b/platform/javascript/export/export.cpp
index 9591850662..78e60af3e0 100644
--- a/platform/javascript/export/export.cpp
+++ b/platform/javascript/export/export.cpp
@@ -74,6 +74,9 @@ public:
 		r_features->push_back(get_os_name());
 	}
 
+	virtual void resolve_platform_feature_priorities(const Ref<EditorExportPreset> &p_preset, Set<String> &p_features) {
+	}
+
 	EditorExportPlatformJavaScript();
 };
 
@@ -95,7 +98,7 @@ void EditorExportPlatformJavaScript::_fix_html(Vector<uint8_t> &p_html, const Re
 	CharString cs = str_export.utf8();
 	p_html.resize(cs.length());
 	for (int i = 0; i < cs.length(); i++) {
-		p_html[i] = cs[i];
+		p_html.write[i] = cs[i];
 	}
 }
 
@@ -140,14 +143,35 @@ Ref<Texture> EditorExportPlatformJavaScript::get_logo() const {
 
 bool EditorExportPlatformJavaScript::can_export(const Ref<EditorExportPreset> &p_preset, String &r_error, bool &r_missing_templates) const {
 
-	r_missing_templates = false;
+	bool valid = false;
+	String err;
+
+	if (find_export_template(EXPORT_TEMPLATE_WEBASSEMBLY_RELEASE) != "")
+		valid = true;
+	else if (find_export_template(EXPORT_TEMPLATE_WEBASSEMBLY_DEBUG) != "")
+		valid = true;
+
+	if (p_preset->get("custom_template/debug") != "") {
+		if (FileAccess::exists(p_preset->get("custom_template/debug"))) {
+			valid = true;
+		} else {
+			err += "Custom debug template not found.\n";
+		}
+	}
+
+	if (p_preset->get("custom_template/release") != "") {
+		if (FileAccess::exists(p_preset->get("custom_template/release"))) {
+			valid = true;
+		} else {
+			err += "Custom release template not found.\n";
+		}
+	}
 
-	if (find_export_template(EXPORT_TEMPLATE_WEBASSEMBLY_RELEASE) == String())
-		r_missing_templates = true;
-	else if (find_export_template(EXPORT_TEMPLATE_WEBASSEMBLY_DEBUG) == String())
-		r_missing_templates = true;
+	if (!err.empty())
+		r_error = err;
 
-	return !r_missing_templates;
+	r_missing_templates = !valid;
+	return valid;
 }
 
 String EditorExportPlatformJavaScript::get_binary_extension(const Ref<EditorExportPreset> &p_preset) const {