Bug 1668757 - Fix lifetime extension issues with 0-length literals. r=xpcom-reviewers,nika

Differential Revision: https://phabricator.services.mozilla.com/D92179

dom/xslt/xslt/txInstructions.cpp

@@ -287,10 +287,8 @@ nsresult txCopy::execute(txExecutionState& aEs) {
   switch (txXPathNodeUtils::getNodeType(node)) {
     case txXPathNodeType::DOCUMENT_NODE:
     case txXPathNodeType::DOCUMENT_FRAGMENT_NODE: {
-      const nsString& empty = u""_ns;
-
       // "close" current element to ensure that no attributes are added
-      rv = aEs.mResultHandler->characters(empty, false);
+      rv = aEs.mResultHandler->characters(u""_ns, false);
       NS_ENSURE_SUCCESS(rv, rv);
 
       rv = aEs.pushBool(false);

editor/libeditor/HTMLEditorDataTransfer.cpp

@@ -2180,8 +2180,8 @@ nsresult HTMLEditor::PasteNoFormattingAsAction(int32_t aSelectionType,
     return rv;
   }
 
-  const nsString& empty = u""_ns;
-  rv = InsertFromTransferable(transferable, nullptr, empty, empty, false, true);
+  rv = InsertFromTransferable(transferable, nullptr, u""_ns, u""_ns, false,
+                              true);
   NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
                        "HTMLEditor::InsertFromTransferable() failed");
   return EditorBase::ToGenericNSResult(rv);

widget/windows/nsDataObj.cpp

@@ -430,7 +430,7 @@ STDMETHODIMP nsDataObj::CMemStream::Stat(STATSTG* statstg, DWORD dwFlags) {
   memset((void*)statstg, 0, sizeof(STATSTG));
 
   if (dwFlags != STATFLAG_NONAME) {
-    const nsString& wideFileName = u""_ns;
+    const nsString& wideFileName = EmptyString();
 
     uint32_t nMaxNameLength = (wideFileName.Length() * 2) + 2;
     void* retBuf = CoTaskMemAlloc(nMaxNameLength);  // freed by caller