MSHTML vbufBackend: if the language cannot be found out from the curr…

…ent DOM node, and our buffer does not have any parents above this node, then go up the DOM node's parents looking for a valid lang attribute. This makes sure that NVDa notices the language for a document in MSHTML when its placed as an attribute on the HTML tag, or if its placed on a tag marked as an application or dialog ARIA role but there is an embedded document. Fixes #1782.

nvdaHelper/vbufBackends/mshtml/mshtml.cpp

@@ -737,16 +737,33 @@ VBufStorage_fieldNode_t* MshtmlVBufBackend_t::fillVBuf(VBufStorage_buffer_t* buf
 
 	//Find out the language
 	wstring language=L"";
-	IHTMLElement* pHTMLElement=NULL;
-	if(pHTMLDOMNode->QueryInterface(IID_IHTMLElement,(void**)&pHTMLElement)==S_OK) {
-		VARIANT v;
-		if(pHTMLElement->getAttribute(L"lang",2,&v)==S_OK) {
-			if(v.vt==VT_BSTR&&v.bstrVal) {
-				language=v.bstrVal;
+	//Try getting it from this DOMNode,
+	//Else if this is the root of our buffer, then keep going up the actual DOM
+	//E.g. will hit HTML tag etc
+	IHTMLDOMNode* pHTMLDOMNodeTemp=pHTMLDOMNode;
+	pHTMLDOMNodeTemp->AddRef();
+	while(pHTMLDOMNodeTemp) {
+		IHTMLElement* pHTMLElement=NULL;
+		if(pHTMLDOMNodeTemp->QueryInterface(IID_IHTMLElement,(void**)&pHTMLElement)==S_OK&&pHTMLElement) {
+			VARIANT v;
+			if(pHTMLElement->getAttribute(L"lang",2,&v)==S_OK) {
+				if(v.vt==VT_BSTR&&v.bstrVal) {
+					language=v.bstrVal;
+				}
+				VariantClear(&v);
+			}
+			pHTMLElement->Release();
+		}
+		if(!parentNode&&language.empty()) {
+			IHTMLDOMNode* pHTMLDOMNodeTempParent=NULL;
+			if(pHTMLDOMNodeTemp->get_parentNode(&pHTMLDOMNodeTempParent)==S_OK&&pHTMLDOMNodeTempParent) {
+				pHTMLDOMNodeTemp->Release();
+				pHTMLDOMNodeTemp=pHTMLDOMNodeTempParent;
+				continue;
 			}
-			VariantClear(&v);
 		}
-		pHTMLElement->Release();
+		pHTMLDOMNodeTemp->Release();
+		pHTMLDOMNodeTemp=NULL;
 	}
 	if(parentNode&&language.empty()) {
 		language=static_cast<MshtmlVBufStorage_controlFieldNode_t*>(parentNode)->language;