diff --git a/mozilla/editor/libeditor/html/TextEditorTest.cpp b/mozilla/editor/libeditor/html/TextEditorTest.cpp
index f8541b326f5..31a5304dbb4 100644
--- a/mozilla/editor/libeditor/html/TextEditorTest.cpp
+++ b/mozilla/editor/libeditor/html/TextEditorTest.cpp
@@ -157,7 +157,7 @@ nsresult TextEditorTest::TestTextProperties()
   TEST_RESULT(result);
   TEST_POINTER(doc.get());
   nsCOMPtr<nsIDOMNodeList>nodeList;
-  nsAutoString textTag; textTag.AssignWithConversion("__moz_text");
+  nsAutoString textTag(NS_LITERAL_STRING("__moz_text"));
   result = doc->GetElementsByTagName(textTag, getter_AddRefs(nodeList));
   TEST_RESULT(result);
   TEST_POINTER(nodeList.get());
diff --git a/mozilla/editor/libeditor/html/nsEditProperty.cpp b/mozilla/editor/libeditor/html/nsEditProperty.cpp
index 4fdc555caa9..6d35ccfbc3a 100644
--- a/mozilla/editor/libeditor/html/nsEditProperty.cpp
+++ b/mozilla/editor/libeditor/html/nsEditProperty.cpp
@@ -230,7 +230,7 @@ nsEditProperty::nsEditProperty()
 
   // special
   if ( (nsIEditProperty::allProperties = new nsString) != nsnull )
-    nsIEditProperty::allProperties->AssignWithConversion("moz_allproperties");
+    nsIEditProperty::allProperties->Assign(NS_LITERAL_STRING("moz_allproperties"));
 }
 
 nsEditProperty::~nsEditProperty()
diff --git a/mozilla/editor/libeditor/html/nsHTMLDataTransfer.cpp b/mozilla/editor/libeditor/html/nsHTMLDataTransfer.cpp
index d94cffec223..ee53f96957a 100644
--- a/mozilla/editor/libeditor/html/nsHTMLDataTransfer.cpp
+++ b/mozilla/editor/libeditor/html/nsHTMLDataTransfer.cpp
@@ -698,7 +698,7 @@ NS_IMETHODIMP nsHTMLEditor::InsertFromTransferable(nsITransferable *transferable
 #ifdef DEBUG_clipboard
     printf("Got flavor [%s]\n", bestFlavor);
 #endif
-    if (flavor.EqualsWithConversion(kHTMLMime))
+    if (flavor.Equals(NS_LITERAL_STRING(kHTMLMime)))
     {
       nsCOMPtr<nsISupportsWString> textDataObj ( do_QueryInterface(genericDataObj) );
       if (textDataObj && len > 0)
@@ -714,7 +714,7 @@ NS_IMETHODIMP nsHTMLEditor::InsertFromTransferable(nsITransferable *transferable
           nsMemory::Free(text);
       }
     }
-    else if (flavor.EqualsWithConversion(kUnicodeMime))
+    else if (flavor.Equals(NS_LITERAL_STRING(kUnicodeMime)))
     {
       nsCOMPtr<nsISupportsWString> textDataObj ( do_QueryInterface(genericDataObj) );
       if (textDataObj && len > 0)
@@ -730,7 +730,7 @@ NS_IMETHODIMP nsHTMLEditor::InsertFromTransferable(nsITransferable *transferable
           nsMemory::Free(text);
       }
     }
-    else if (flavor.EqualsWithConversion(kFileMime))
+    else if (flavor.Equals(NS_LITERAL_STRING(kFileMime)))
     {
       nsCOMPtr<nsIFile> fileObj ( do_QueryInterface(genericDataObj) );
       if (fileObj && len > 0)
@@ -766,17 +766,17 @@ NS_IMETHODIMP nsHTMLEditor::InsertFromTransferable(nsITransferable *transferable
             len = strlen(urltext);
             if ( insertAsImage )
             {
-              stuffToPaste.AssignWithConversion ( "<IMG src=\"", 10);
+              stuffToPaste.Assign(NS_LITERAL_STRING("<IMG src=\""));
               stuffToPaste.AppendWithConversion ( urltext, len );
-              stuffToPaste.AppendWithConversion ( "\" alt=\"\" >" );
+              stuffToPaste.Append(NS_LITERAL_STRING("\" alt=\"\" >"));
             }
             else /* insert as link */
             {
-              stuffToPaste.AssignWithConversion ( "<A href=\"" );
+              stuffToPaste.Assign(NS_LITERAL_STRING("<A href=\""));
               stuffToPaste.AppendWithConversion ( urltext, len );
-              stuffToPaste.AppendWithConversion ( "\">" );
+              stuffToPaste.Append(NS_LITERAL_STRING("\">"));
               stuffToPaste.AppendWithConversion ( urltext, len );
-              stuffToPaste.AppendWithConversion ( "</A>" );
+              stuffToPaste.Append(NS_LITERAL_STRING("</A>"));
             }
             nsAutoEditBatch beginBatching(this);
             rv = InsertHTML(stuffToPaste);
@@ -785,7 +785,7 @@ NS_IMETHODIMP nsHTMLEditor::InsertFromTransferable(nsITransferable *transferable
         }
       }
     }
-    else if (flavor.EqualsWithConversion(kJPEGImageMime))
+    else if (flavor.Equals(NS_LITERAL_STRING(kJPEGImageMime)))
     {
       // Insert Image code here
       printf("Don't know how to insert an image yet!\n");
@@ -1409,7 +1409,7 @@ NS_IMETHODIMP nsHTMLEditor::PasteAsCitedQuotation(const nsAReadableString & aCit
   if (!handled)
   {
     nsCOMPtr<nsIDOMNode> newNode;
-    nsAutoString tag; tag.AssignWithConversion("blockquote");
+    nsAutoString tag(NS_LITERAL_STRING("blockquote"));
     res = DeleteSelectionAndCreateNode(tag, getter_AddRefs(newNode));
     if (NS_FAILED(res)) return res;
     if (!newNode) return NS_ERROR_NULL_POINTER;
@@ -1418,8 +1418,8 @@ NS_IMETHODIMP nsHTMLEditor::PasteAsCitedQuotation(const nsAReadableString & aCit
     nsCOMPtr<nsIDOMElement> newElement (do_QueryInterface(newNode));
     if (newElement)
     {
-      nsAutoString type; type.AssignWithConversion("type");
-      nsAutoString cite; cite.AssignWithConversion("cite");
+      nsAutoString type(NS_LITERAL_STRING("type"));
+      nsAutoString cite(NS_LITERAL_STRING("cite"));
       newElement->SetAttribute(type, cite);
     }
 
@@ -1481,7 +1481,7 @@ NS_IMETHODIMP nsHTMLEditor::PasteAsPlaintextQuotation(PRInt32 aSelectionType)
 #endif
     nsAutoString flavor; flavor.AssignWithConversion(flav);
     nsAutoString stuffToPaste;
-    if (flavor.EqualsWithConversion(kUnicodeMime))
+    if (flavor.Equals(NS_LITERAL_STRING(kUnicodeMime)))
     {
       nsCOMPtr<nsISupportsWString> textDataObj ( do_QueryInterface(genericDataObj) );
       if (textDataObj && len > 0)
@@ -1630,7 +1630,7 @@ nsHTMLEditor::InsertAsCitedQuotation(const nsAReadableString & aQuotedText,
     if (cancel) return NS_OK; // rules canceled the operation
     if (!handled)
     {
-      nsAutoString tag; tag.AssignWithConversion("blockquote");
+      nsAutoString tag(NS_LITERAL_STRING("blockquote"));
       res = DeleteSelectionAndCreateNode(tag, getter_AddRefs(newNode));
       if (NS_FAILED(res)) return res;
       if (!newNode) return NS_ERROR_NULL_POINTER;
@@ -1639,8 +1639,8 @@ nsHTMLEditor::InsertAsCitedQuotation(const nsAReadableString & aQuotedText,
       nsCOMPtr<nsIDOMElement> newElement (do_QueryInterface(newNode));
       if (newElement)
       {
-        nsAutoString type; type.AssignWithConversion("type");
-        nsAutoString cite; cite.AssignWithConversion("cite");
+        nsAutoString type(NS_LITERAL_STRING("type"));
+        nsAutoString cite(NS_LITERAL_STRING("cite"));
         newElement->SetAttribute(type, cite);
 
         if (aCitation.Length() > 0)
diff --git a/mozilla/editor/libeditor/html/nsHTMLEditRules.cpp b/mozilla/editor/libeditor/html/nsHTMLEditRules.cpp
index 6f1a7b3cb3e..ceb9ff0ebe6 100644
--- a/mozilla/editor/libeditor/html/nsHTMLEditRules.cpp
+++ b/mozilla/editor/libeditor/html/nsHTMLEditRules.cpp
@@ -734,7 +734,7 @@ nsHTMLEditRules::GetAlignment(PRBool *aMixed, nsIHTMLEditor::EAlignment *aAlign)
       nsCOMPtr<nsIDOMElement> elem = do_QueryInterface(nodeToExamine);
       if (elem)
       {
-        nsAutoString typeAttrName; typeAttrName.Assign(NS_LITERAL_STRING("align"));
+        nsAutoString typeAttrName(NS_LITERAL_STRING("align"));
         nsAutoString typeAttrVal;
         res = elem->GetAttribute(typeAttrName, typeAttrVal);
         typeAttrVal.ToLowerCase();
@@ -868,9 +868,8 @@ nsHTMLEditRules::GetParagraphState(PRBool *aMixed, nsAWritableString &outFormat)
   outFormat.Truncate(0);
   
   PRBool bMixed = PR_FALSE;
-  nsAutoString formatStr; 
   // using "x" as an uninitialized value, since "" is meaningful
-  formatStr.Assign(NS_LITERAL_STRING("x"));
+  nsAutoString formatStr(NS_LITERAL_STRING("x")); 
   
   nsCOMPtr<nsISupportsArray> arrayOfNodes;
   nsresult res = GetParagraphFormatNodes(address_of(arrayOfNodes), PR_TRUE);
@@ -1086,7 +1085,7 @@ nsHTMLEditRules::WillInsertText(PRInt32          aAction,
   if (NS_FAILED(res)) return res;
 
   // dont put text in places that cant have it
-  nsAutoString textTag; textTag.Assign(NS_LITERAL_STRING("__moz_text"));
+  nsAutoString textTag(NS_LITERAL_STRING("__moz_text"));
   if (!mHTMLEditor->IsTextNode(selNode) && !mHTMLEditor->CanContainTag(selNode, textTag))
     return NS_ERROR_FAILURE;
 
@@ -1182,7 +1181,7 @@ nsHTMLEditRules::WillInsertText(PRInt32          aAction,
       NS_NAMED_LITERAL_STRING(tabStr, "\t");
       NS_NAMED_LITERAL_STRING(newlineStr, "\n");
       char specialChars[] = {'\t','\n',0};
-      nsAutoString tabString; tabString.Assign(NS_LITERAL_STRING("    "));
+      nsAutoString tabString(NS_LITERAL_STRING("    "));
       while (unicodeBuf && (pos != -1) && (pos < (PRInt32)inString->Length()))
       {
         PRInt32 oldPos = pos;
@@ -2527,8 +2526,7 @@ nsHTMLEditRules::WillMakeDefListItem(nsISelection *aSelection,
                                      PRBool *aHandled)
 {
   // for now we let WillMakeList handle this
-  nsAutoString listType; 
-  listType.Assign(NS_LITERAL_STRING("dl"));
+  nsAutoString listType(NS_LITERAL_STRING("dl"));
   return WillMakeList(aSelection, &listType, aEntireList, aCancel, aHandled, aItemType);
 }
 
@@ -2746,7 +2744,7 @@ nsHTMLEditRules::WillIndent(nsISelection *aSelection, PRBool *aCancel, PRBool *
   {
     nsCOMPtr<nsIDOMNode> parent, theBlock;
     PRInt32 offset;
-    nsAutoString quoteType; quoteType.Assign(NS_LITERAL_STRING("blockquote"));
+    nsAutoString quoteType(NS_LITERAL_STRING("blockquote"));
     
     // get selection location
     res = mHTMLEditor->GetStartNodeAndOffset(aSelection, address_of(parent), &offset);
@@ -2867,7 +2865,7 @@ nsHTMLEditRules::WillIndent(nsISelection *aSelection, PRBool *aCancel, PRBool *
         // or if this node doesn't go in blockquote we used earlier.
         if (!curQuote) 
         {
-          nsAutoString quoteType; quoteType.Assign(NS_LITERAL_STRING("blockquote"));
+          nsAutoString quoteType(NS_LITERAL_STRING("blockquote"));
           res = SplitAsNeeded(&quoteType, address_of(curParent), &offset);
           if (NS_FAILED(res)) return res;
           res = mHTMLEditor->CreateNode(quoteType, curParent, offset, getter_AddRefs(curQuote));
@@ -3388,7 +3386,7 @@ nsHTMLEditRules::WillAlign(nsISelection *aSelection,
   {
     PRInt32 offset;
     nsCOMPtr<nsIDOMNode> brNode, parent, theDiv, sib;
-    nsAutoString divType; divType.Assign(NS_LITERAL_STRING("div"));
+    nsAutoString divType(NS_LITERAL_STRING("div"));
     res = mHTMLEditor->GetStartNodeAndOffset(aSelection, address_of(parent), &offset);
     if (NS_FAILED(res)) return res;
     res = SplitAsNeeded(&divType, address_of(parent), &offset);
@@ -3455,7 +3453,7 @@ nsHTMLEditRules::WillAlign(nsISelection *aSelection,
     if (nsHTMLEditUtils::SupportsAlignAttr(curNode))
     {
       nsCOMPtr<nsIDOMElement> divElem = do_QueryInterface(curNode);
-      nsAutoString attr; attr.Assign(NS_LITERAL_STRING("align"));
+      nsAutoString attr(NS_LITERAL_STRING("align"));
       res = mHTMLEditor->SetAttribute(divElem, attr, *alignType);
       if (NS_FAILED(res)) return res;
       // clear out curDiv so that we don't put nodes after this one into it
@@ -3488,7 +3486,7 @@ nsHTMLEditRules::WillAlign(nsISelection *aSelection,
     // or if this node doesn't go in div we used earlier.
     if (!curDiv || transitionList[i])
     {
-      nsAutoString divType; divType.Assign(NS_LITERAL_STRING("div"));
+      nsAutoString divType(NS_LITERAL_STRING("div"));
       res = SplitAsNeeded(&divType, address_of(curParent), &offset);
       if (NS_FAILED(res)) return res;
       res = mHTMLEditor->CreateNode(divType, curParent, offset, getter_AddRefs(curDiv));
@@ -3497,7 +3495,7 @@ nsHTMLEditRules::WillAlign(nsISelection *aSelection,
       mNewBlock = curDiv;
       // set up the alignment on the div
       nsCOMPtr<nsIDOMElement> divElem = do_QueryInterface(curDiv);
-      nsAutoString attr; attr.Assign(NS_LITERAL_STRING("align"));
+      nsAutoString attr(NS_LITERAL_STRING("align"));
       res = mHTMLEditor->SetAttribute(divElem, attr, *alignType);
       if (NS_FAILED(res)) return res;
       // curDiv is now the correct thing to put curNode in
@@ -3573,19 +3571,19 @@ nsHTMLEditRules::AlignBlockContents(nsIDOMNode *aNode, const nsAReadableString *
     // the cell already has a div containing all of it's content: just
     // act on this div.
     nsCOMPtr<nsIDOMElement> divElem = do_QueryInterface(firstChild);
-    nsAutoString attr; attr.Assign(NS_LITERAL_STRING("align"));
+    nsAutoString attr(NS_LITERAL_STRING("align"));
     res = mHTMLEditor->SetAttribute(divElem, attr, *alignType);
     if (NS_FAILED(res)) return res;
   }
   else
   {
     // else we need to put in a div, set the alignment, and toss in all the children
-    nsAutoString divType; divType.Assign(NS_LITERAL_STRING("div"));
+    nsAutoString divType(NS_LITERAL_STRING("div"));
     res = mHTMLEditor->CreateNode(divType, aNode, 0, getter_AddRefs(divNode));
     if (NS_FAILED(res)) return res;
     // set up the alignment on the div
     nsCOMPtr<nsIDOMElement> divElem = do_QueryInterface(divNode);
-    nsAutoString attr; attr.Assign(NS_LITERAL_STRING("align"));
+    nsAutoString attr(NS_LITERAL_STRING("align"));
     res = mHTMLEditor->SetAttribute(divElem, attr, *alignType);
     if (NS_FAILED(res)) return res;
     // tuck the children into the end of the active div
@@ -5293,7 +5291,7 @@ nsHTMLEditRules::MakeBlockquote(nsISupportsArray *arrayOfNodes)
     // if no curBlock, make one
     if (!curBlock)
     {
-      nsAutoString quoteType; quoteType.Assign(NS_LITERAL_STRING("blockquote"));
+      nsAutoString quoteType(NS_LITERAL_STRING("blockquote"));
       res = SplitAsNeeded(&quoteType, address_of(curParent), &offset);
       if (NS_FAILED(res)) return res;
       res = mHTMLEditor->CreateNode(quoteType, curParent, offset, getter_AddRefs(curBlock));
diff --git a/mozilla/editor/libeditor/html/nsHTMLEditUtils.cpp b/mozilla/editor/libeditor/html/nsHTMLEditUtils.cpp
index cb9f4076545..fc2c6385191 100644
--- a/mozilla/editor/libeditor/html/nsHTMLEditUtils.cpp
+++ b/mozilla/editor/libeditor/html/nsHTMLEditUtils.cpp
@@ -77,12 +77,12 @@ nsHTMLEditUtils::IsHeader(nsIDOMNode *node)
   nsAutoString tag;
   nsEditor::GetTagString(node,tag);
   tag.ToLowerCase();
-  if ( (tag.EqualsWithConversion("h1")) ||
-       (tag.EqualsWithConversion("h2")) ||
-       (tag.EqualsWithConversion("h3")) ||
-       (tag.EqualsWithConversion("h4")) ||
-       (tag.EqualsWithConversion("h5")) ||
-       (tag.EqualsWithConversion("h6")) )
+  if ( (tag.Equals(NS_LITERAL_STRING("h1"))) ||
+       (tag.Equals(NS_LITERAL_STRING("h2"))) ||
+       (tag.Equals(NS_LITERAL_STRING("h3"))) ||
+       (tag.Equals(NS_LITERAL_STRING("h4"))) ||
+       (tag.Equals(NS_LITERAL_STRING("h5"))) ||
+       (tag.Equals(NS_LITERAL_STRING("h6"))) )
   {
     return PR_TRUE;
   }
@@ -110,9 +110,9 @@ nsHTMLEditUtils::IsListItem(nsIDOMNode *node)
   nsAutoString tag;
   nsEditor::GetTagString(node,tag);
   tag.ToLowerCase();
-  if (tag.EqualsWithConversion("li") ||
-      tag.EqualsWithConversion("dd") ||
-      tag.EqualsWithConversion("dt"))
+  if (tag.Equals(NS_LITERAL_STRING("li")) ||
+      tag.Equals(NS_LITERAL_STRING("dd")) ||
+      tag.Equals(NS_LITERAL_STRING("dt")))
   {
     return PR_TRUE;
   }
@@ -129,10 +129,10 @@ nsHTMLEditUtils::IsTableElement(nsIDOMNode *node)
   NS_PRECONDITION(node, "null node passed to nsHTMLEditor::IsTableElement");
   nsAutoString tagName;
   nsEditor::GetTagString(node,tagName);
-  if (tagName.EqualsWithConversion("table") || tagName.EqualsWithConversion("tr") || 
-      tagName.EqualsWithConversion("td")    || tagName.EqualsWithConversion("th") ||
-      tagName.EqualsWithConversion("thead") || tagName.EqualsWithConversion("tfoot") ||
-      tagName.EqualsWithConversion("tbody") || tagName.EqualsWithConversion("caption"))
+  if (tagName.Equals(NS_LITERAL_STRING("table")) || tagName.Equals(NS_LITERAL_STRING("tr")) || 
+      tagName.Equals(NS_LITERAL_STRING("td"))    || tagName.Equals(NS_LITERAL_STRING("th")) ||
+      tagName.Equals(NS_LITERAL_STRING("thead")) || tagName.Equals(NS_LITERAL_STRING("tfoot")) ||
+      tagName.Equals(NS_LITERAL_STRING("tbody")) || tagName.Equals(NS_LITERAL_STRING("caption")))
   {
     return PR_TRUE;
   }
@@ -169,7 +169,7 @@ nsHTMLEditUtils::IsTableCell(nsIDOMNode *node)
   nsAutoString tag;
   nsEditor::GetTagString(node,tag);
   tag.ToLowerCase();
-  if (tag.EqualsWithConversion("td") || tag.EqualsWithConversion("th"))
+  if (tag.Equals(NS_LITERAL_STRING("td")) || tag.Equals(NS_LITERAL_STRING("th")))
   {
     return PR_TRUE;
   }
@@ -187,9 +187,9 @@ nsHTMLEditUtils::IsTableCellOrCaption(nsIDOMNode *node)
   nsAutoString tag;
   nsEditor::GetTagString(node,tag);
   tag.ToLowerCase();
-  if (tag.EqualsWithConversion("td") || 
-      tag.EqualsWithConversion("th") ||
-      tag.EqualsWithConversion("caption") )
+  if (tag.Equals(NS_LITERAL_STRING("td")) || 
+      tag.Equals(NS_LITERAL_STRING("th")) ||
+      tag.Equals(NS_LITERAL_STRING("caption")) )
   {
     return PR_TRUE;
   }
@@ -207,9 +207,9 @@ nsHTMLEditUtils::IsList(nsIDOMNode *node)
   nsAutoString tag;
   nsEditor::GetTagString(node,tag);
   tag.ToLowerCase();
-  if ( (tag.EqualsWithConversion("dl")) ||
-       (tag.EqualsWithConversion("ol")) ||
-       (tag.EqualsWithConversion("ul")) )
+  if ( (tag.Equals(NS_LITERAL_STRING("dl"))) ||
+       (tag.Equals(NS_LITERAL_STRING("ol"))) ||
+       (tag.Equals(NS_LITERAL_STRING("ul"))) )
   {
     return PR_TRUE;
   }
@@ -368,7 +368,7 @@ nsHTMLEditUtils::IsMailCite(nsIDOMNode *node)
   if (IsBlockquote(node))
   {
     nsCOMPtr<nsIDOMElement> bqElem = do_QueryInterface(node);
-    nsAutoString typeAttrName; typeAttrName.AssignWithConversion("type");
+    nsAutoString typeAttrName(NS_LITERAL_STRING("type"));
     nsAutoString typeAttrVal;
     nsresult res = bqElem->GetAttribute(typeAttrName, typeAttrVal);
     typeAttrVal.ToLowerCase();
@@ -439,22 +439,22 @@ nsHTMLEditUtils::SupportsAlignAttr(nsIDOMNode * aNode)
   nsAutoString tag;
   nsEditor::GetTagString(aNode, tag);
   tag.ToLowerCase();
-  if (tag.EqualsWithConversion("hr") ||
-      tag.EqualsWithConversion("table") ||
-      tag.EqualsWithConversion("tbody") ||
-      tag.EqualsWithConversion("tfoot") ||
-      tag.EqualsWithConversion("thead") ||
-      tag.EqualsWithConversion("tr") ||
-      tag.EqualsWithConversion("td") ||
-      tag.EqualsWithConversion("th") ||
-      tag.EqualsWithConversion("div") ||
-      tag.EqualsWithConversion("p") ||
-      tag.EqualsWithConversion("h1") ||
-      tag.EqualsWithConversion("h2") ||
-      tag.EqualsWithConversion("h3") ||
-      tag.EqualsWithConversion("h4") ||
-      tag.EqualsWithConversion("h5") ||
-      tag.EqualsWithConversion("h6")) {
+  if (tag.Equals(NS_LITERAL_STRING("hr")) ||
+      tag.Equals(NS_LITERAL_STRING("table")) ||
+      tag.Equals(NS_LITERAL_STRING("tbody")) ||
+      tag.Equals(NS_LITERAL_STRING("tfoot")) ||
+      tag.Equals(NS_LITERAL_STRING("thead")) ||
+      tag.Equals(NS_LITERAL_STRING("tr")) ||
+      tag.Equals(NS_LITERAL_STRING("td")) ||
+      tag.Equals(NS_LITERAL_STRING("th")) ||
+      tag.Equals(NS_LITERAL_STRING("div")) ||
+      tag.Equals(NS_LITERAL_STRING("p")) ||
+      tag.Equals(NS_LITERAL_STRING("h1")) ||
+      tag.Equals(NS_LITERAL_STRING("h2")) ||
+      tag.Equals(NS_LITERAL_STRING("h3")) ||
+      tag.Equals(NS_LITERAL_STRING("h4")) ||
+      tag.Equals(NS_LITERAL_STRING("h5")) ||
+      tag.Equals(NS_LITERAL_STRING("h6"))) {
     return PR_TRUE;
   }
   return PR_FALSE;
diff --git a/mozilla/editor/libeditor/html/nsHTMLEditor.cpp b/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
index d1b05fb7f64..ad6de8d4412 100644
--- a/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
+++ b/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
@@ -1306,7 +1306,7 @@ NS_IMETHODIMP nsHTMLEditor::CreateBRImpl(nsCOMPtr<nsIDOMNode> *aInOutParent,
   nsCOMPtr<nsIDOMNode> node = *aInOutParent;
   PRInt32 theOffset = *aInOutOffset;
   nsCOMPtr<nsIDOMCharacterData> nodeAsText = do_QueryInterface(node);
-  nsAutoString brType; brType.Assign(NS_LITERAL_STRING("br"));
+  nsAutoString brType(NS_LITERAL_STRING("br"));
   nsCOMPtr<nsIDOMNode> brNode;
   if (nodeAsText)  
   {
@@ -1542,7 +1542,7 @@ nsHTMLEditor::ReplaceHeadContentsWithHTML(const nsAReadableString& aSourceToInse
   // Do not use nsAutoRules -- rules code won't let us insert in <head>
   // Use the head node as a parent and delete/insert directly
   nsCOMPtr<nsIDOMNodeList>nodeList; 
-  nsAutoString headTag; headTag.Assign(NS_LITERAL_STRING("head")); 
+  nsAutoString headTag(NS_LITERAL_STRING("head")); 
 
   nsCOMPtr<nsIDOMDocument> doc = do_QueryReferent(mDocWeak);
   if (!doc) return NS_ERROR_NOT_INITIALIZED;
@@ -2116,7 +2116,7 @@ nsHTMLEditor::GetBackgroundColorState(PRBool *aMixed, nsAWritableString &aOutCol
   nsresult res = GetSelectedOrParentTableElement(*getter_AddRefs(element), tagName, selectedCount);
   if (NS_FAILED(res)) return res;
 
-  nsAutoString styleName; styleName.Assign(NS_LITERAL_STRING("bgcolor"));
+  nsAutoString styleName(NS_LITERAL_STRING("bgcolor"));
 
   while (element)
   {
@@ -2258,7 +2258,7 @@ nsHTMLEditor::MakeOrChangeList(const nsAReadableString& aListType, PRBool entire
       res = CreateNode(aListType, parent, offset, getter_AddRefs(newList));
       if (NS_FAILED(res)) return res;
       // make a list item
-      nsAutoString tag; tag.Assign(NS_LITERAL_STRING("li"));
+      nsAutoString tag(NS_LITERAL_STRING("li"));
       nsCOMPtr<nsIDOMNode> newItem;
       res = CreateNode(tag, newList, 0, getter_AddRefs(newItem));
       if (NS_FAILED(res)) return res;
@@ -2444,7 +2444,7 @@ nsHTMLEditor::Indent(const nsAReadableString& aIndent)
     if (!node) res = NS_ERROR_FAILURE;
     if (NS_FAILED(res)) return res;
   
-    nsAutoString inward; inward.Assign(NS_LITERAL_STRING("indent"));
+    nsAutoString inward(NS_LITERAL_STRING("indent"));
     if (aIndent == inward)
     {
       if (isCollapsed)
@@ -3426,7 +3426,7 @@ static nsresult SetSelectionAroundHeadChildren(nsCOMPtr<nsISelection> aSelection
   nsresult res = NS_OK;
   // Set selection around <head> node
   nsCOMPtr<nsIDOMNodeList>nodeList; 
-  nsAutoString headTag; headTag.Assign(NS_LITERAL_STRING("head")); 
+  nsAutoString headTag(NS_LITERAL_STRING("head")); 
 
   nsCOMPtr<nsIDOMDocument> doc = do_QueryReferent(aDocWeak);
   if (!doc) return NS_ERROR_NOT_INITIALIZED;
diff --git a/mozilla/editor/libeditor/html/nsHTMLEditorStyle.cpp b/mozilla/editor/libeditor/html/nsHTMLEditorStyle.cpp
index 784a480466d..ee6c57c2f34 100644
--- a/mozilla/editor/libeditor/html/nsHTMLEditorStyle.cpp
+++ b/mozilla/editor/libeditor/html/nsHTMLEditorStyle.cpp
@@ -1410,11 +1410,12 @@ nsHTMLEditor::RelativeFontChangeOnTextNode( PRInt32 aSizeChange,
     res = SplitNode(node, aStartOffset, getter_AddRefs(tmp));
     if (NS_FAILED(res)) return res;
   }
-  
+
+  nsAutoString nodeType(aSizeChange==1 ? NS_LITERAL_STRING("big") : NS_LITERAL_STRING("small"));
   // look for siblings that are correct type of node
   nsCOMPtr<nsIDOMNode> sibling;
   GetPriorHTMLSibling(node, address_of(sibling));
-  if (sibling && NodeIsType(sibling, NS_ConvertASCIItoUCS2(aSizeChange==1 ? "big" : "small")))
+  if (sibling && NodeIsType(sibling, nodeType))
   {
     // previous sib is already right kind of inline node; slide this over into it
     res = MoveNode(node, sibling, -1);
@@ -1422,7 +1423,7 @@ nsHTMLEditor::RelativeFontChangeOnTextNode( PRInt32 aSizeChange,
   }
   sibling = nsnull;
   GetNextHTMLSibling(node, address_of(sibling));
-  if (sibling && NodeIsType(sibling, NS_ConvertASCIItoUCS2(aSizeChange==1 ? "big" : "small")))
+  if (sibling && NodeIsType(sibling, nodeType))
   {
     // following sib is already right kind of inline node; slide this over into it
     res = MoveNode(node, sibling, 0);
@@ -1430,7 +1431,7 @@ nsHTMLEditor::RelativeFontChangeOnTextNode( PRInt32 aSizeChange,
   }
   
   // else reparent the node inside font node with appropriate relative size
-  res = InsertContainerAbove(node, address_of(tmp), NS_ConvertASCIItoUCS2(aSizeChange==1 ? "big" : "small"));
+  res = InsertContainerAbove(node, address_of(tmp), nodeType);
   return res;
 }
 
@@ -1452,14 +1453,13 @@ nsHTMLEditor::RelativeFontChangeHelper( PRInt32 aSizeChange,
 
   nsresult res = NS_OK;
   nsAutoString tag;
-  if (aSizeChange == 1) tag.AssignWithConversion("big");
-  else tag.AssignWithConversion("small");
+  if (aSizeChange == 1) tag.Assign(NS_LITERAL_STRING("big"));
+  else tag.Assign(NS_LITERAL_STRING("small"));
   nsCOMPtr<nsIDOMNodeList> childNodes;
   PRInt32 j;
   PRUint32 childCount;
   nsCOMPtr<nsIDOMNode> childNode;
-  nsAutoString attr;
-  attr.AssignWithConversion("size");
+  nsAutoString attr(NS_LITERAL_STRING("size"));
   
   // if this is a font node with size, put big/small inside it
   if (NodeIsType(aNode, nsIEditProperty::font) && HasAttr(aNode, &attr))
@@ -1590,12 +1590,10 @@ nsHTMLEditor::GetFontFaceState(PRBool *aMixed, nsAWritableString &outFace)
   if (!aMixed)
       return NS_ERROR_FAILURE;
   *aMixed = PR_TRUE;
-  //outFace.Assign(NS_LITERAL_STRING(""));
   outFace.SetLength(0);
 
   nsresult res;
-  nsAutoString faceStr;
-  faceStr.Assign(NS_LITERAL_STRING("face"));
+  nsAutoString faceStr(NS_LITERAL_STRING("face"));
   PRBool first, any, all;
   
   
@@ -1635,7 +1633,7 @@ nsHTMLEditor::GetFontColorState(PRBool *aMixed, nsAWritableString &aOutColor)
   aOutColor.SetLength(0);
   
   nsresult res;
-  nsAutoString colorStr; colorStr.Assign(NS_LITERAL_STRING("color"));
+  nsAutoString colorStr(NS_LITERAL_STRING("color"));
   PRBool first, any, all;
   
   res = GetInlinePropertyBase(nsIEditProperty::font, &colorStr, nsnull, &first, &any, &all, &aOutColor);
diff --git a/mozilla/editor/libeditor/html/nsTableEditor.cpp b/mozilla/editor/libeditor/html/nsTableEditor.cpp
index 9eca20adf11..a757001ed3b 100644
--- a/mozilla/editor/libeditor/html/nsTableEditor.cpp
+++ b/mozilla/editor/libeditor/html/nsTableEditor.cpp
@@ -193,7 +193,7 @@ NS_IMETHODIMP nsHTMLEditor::SetColSpan(nsIDOMElement *aCell, PRInt32 aColSpan)
   if (!aCell) return NS_ERROR_NULL_POINTER;
   nsAutoString newSpan;
   newSpan.AppendInt(aColSpan, 10);
-  nsAutoString colSpan; colSpan.AssignWithConversion("colspan");
+  nsAutoString colSpan(NS_LITERAL_STRING("colspan"));
   return SetAttribute(aCell, colSpan, newSpan);
 }
 
@@ -202,7 +202,7 @@ NS_IMETHODIMP nsHTMLEditor::SetRowSpan(nsIDOMElement *aCell, PRInt32 aRowSpan)
   if (!aCell) return NS_ERROR_NULL_POINTER;
   nsAutoString newSpan;
   newSpan.AppendInt(aRowSpan, 10);
-  nsAutoString rowSpan; rowSpan.AssignWithConversion("rowspan");
+  nsAutoString rowSpan(NS_LITERAL_STRING("rowspan"));
   return SetAttribute(aCell, rowSpan, newSpan);
 }
 
@@ -1893,7 +1893,7 @@ nsHTMLEditor::CopyCellBackgroundColor(nsIDOMElement *destCell, nsIDOMElement *so
   if (!destCell || !sourceCell) return NS_ERROR_NULL_POINTER;
 
   // Copy backgournd color to new cell
-  nsAutoString bgcolor; bgcolor.AssignWithConversion("bgcolor");
+  nsAutoString bgcolor(NS_LITERAL_STRING("bgcolor"));
   nsAutoString color;
   PRBool isSet;
   nsresult res = GetAttributeValue(sourceCell, bgcolor, color, &isSet);
@@ -3297,7 +3297,7 @@ nsHTMLEditor::GetSelectedOrParentTableElement(nsIDOMElement* &aTableElement, nsS
   if (NS_FAILED(res)) return res;
   if (!selection) return NS_ERROR_FAILURE;
 
-  nsAutoString tdName; tdName.AssignWithConversion("td");
+  nsAutoString tdName(NS_LITERAL_STRING("td"));
 
   // Try to get the first selected cell
   nsCOMPtr<nsIDOMElement> tableOrCellElement;
@@ -3314,8 +3314,8 @@ nsHTMLEditor::GetSelectedOrParentTableElement(nsIDOMElement* &aTableElement, nsS
   }
   else
   {
-    nsAutoString tableName; tableName.AssignWithConversion("table");
-    nsAutoString trName; trName.AssignWithConversion("tr");
+    nsAutoString tableName(NS_LITERAL_STRING("table"));
+    nsAutoString trName(NS_LITERAL_STRING("tr"));
 
     nsCOMPtr<nsIDOMNode> anchorNode;
     res = selection->GetAnchorNode(getter_AddRefs(anchorNode));
diff --git a/mozilla/editor/libeditor/text/nsPlaintextDataTransfer.cpp b/mozilla/editor/libeditor/text/nsPlaintextDataTransfer.cpp
index 069d462033d..317ed717c5a 100644
--- a/mozilla/editor/libeditor/text/nsPlaintextDataTransfer.cpp
+++ b/mozilla/editor/libeditor/text/nsPlaintextDataTransfer.cpp
@@ -168,7 +168,7 @@ NS_IMETHODIMP nsPlaintextEditor::InsertTextFromTransferable(nsITransferable *tra
     nsAutoTxnsConserveSelection dontSpazMySelection(this);
     nsAutoString flavor, stuffToPaste;
     flavor.AssignWithConversion( bestFlavor );   // just so we can use flavor.Equals()
-    if (flavor.EqualsWithConversion(kUnicodeMime))
+    if (flavor.Equals(NS_LITERAL_STRING(kUnicodeMime)))
     {
       nsCOMPtr<nsISupportsWString> textDataObj ( do_QueryInterface(genericDataObj) );
       if (textDataObj && len > 0)
diff --git a/mozilla/editor/libeditor/text/nsPlaintextEditor.cpp b/mozilla/editor/libeditor/text/nsPlaintextEditor.cpp
index 5c7a0134c26..564f44b1150 100644
--- a/mozilla/editor/libeditor/text/nsPlaintextEditor.cpp
+++ b/mozilla/editor/libeditor/text/nsPlaintextEditor.cpp
@@ -336,7 +336,7 @@ nsPlaintextEditor::SetDocumentCharacterSet(const nsAReadableString & characterSe
                 // not undoable, undo should undo CreateNode 
                 result = metaElement->SetAttribute(NS_LITERAL_STRING("http-equiv"), NS_LITERAL_STRING("Content-Type")); 
                 if (NS_SUCCEEDED(result)) { 
-                  newMetaString.AssignWithConversion("text/html;charset="); 
+                  newMetaString.Assign(NS_LITERAL_STRING("text/html;charset=")); 
                   newMetaString.Append(characterSet); 
                   // not undoable, undo should undo CreateNode 
                   result = metaElement->SetAttribute(NS_LITERAL_STRING("content"), newMetaString); 
@@ -576,7 +576,7 @@ NS_IMETHODIMP nsPlaintextEditor::CreateBRImpl(nsCOMPtr<nsIDOMNode> *aInOutParent
   nsCOMPtr<nsIDOMNode> node = *aInOutParent;
   PRInt32 theOffset = *aInOutOffset;
   nsCOMPtr<nsIDOMCharacterData> nodeAsText = do_QueryInterface(node);
-  nsAutoString brType; brType.AssignWithConversion("br");
+  nsAutoString brType(NS_LITERAL_STRING("br"));
   nsCOMPtr<nsIDOMNode> brNode;
   if (nodeAsText)  
   {
@@ -1024,7 +1024,7 @@ NS_IMETHODIMP nsPlaintextEditor::InsertLineBreak()
   {
     // create the new BR node
     nsCOMPtr<nsIDOMNode> newNode;
-    nsAutoString tag; tag.AssignWithConversion("BR");
+    nsAutoString tag(NS_LITERAL_STRING("BR"));
     res = DeleteSelectionAndCreateNode(tag, getter_AddRefs(newNode));
     if (!newNode) res = NS_ERROR_NULL_POINTER; // don't return here, so DidDoAction is called
     if (NS_SUCCEEDED(res))
@@ -1274,7 +1274,7 @@ nsPlaintextEditor::SetWrapWidth(PRInt32 aWrapColumn)
   if (!bodyElement) return NS_ERROR_NULL_POINTER;
 
   // Get the current style for this body element:
-  nsAutoString styleName; styleName.AssignWithConversion("style");
+  nsAutoString styleName(NS_LITERAL_STRING("style"));
   nsAutoString styleValue;
   res = bodyElement->GetAttribute(styleName, styleValue);
   if (NS_FAILED(res)) return res;
@@ -1289,7 +1289,7 @@ nsPlaintextEditor::SetWrapWidth(PRInt32 aWrapColumn)
   if (styleValue.Length() > 0)
   {
     styleValue.Trim("; \t", PR_FALSE, PR_TRUE);
-    styleValue.AppendWithConversion("; ");
+    styleValue.Append(NS_LITERAL_STRING("; "));
   }
 
   // Make sure we have fixed-width font.  This should be done for us,
@@ -1298,19 +1298,19 @@ nsPlaintextEditor::SetWrapWidth(PRInt32 aWrapColumn)
   PRUint32 flags = 0;
   GetFlags(&flags);
   if ((flags & eEditorEnableWrapHackMask) && aWrapColumn >= 0)
-    styleValue.AppendWithConversion("font-family: -moz-fixed; ");
+    styleValue.Append(NS_LITERAL_STRING("font-family: -moz-fixed; "));
 
   // and now we're ready to set the new whitespace/wrapping style.
   if (aWrapColumn > 0)        // Wrap to a fixed column
   {
-    styleValue.AppendWithConversion("white-space: -moz-pre-wrap; width: ");
+    styleValue.Append(NS_LITERAL_STRING("white-space: -moz-pre-wrap; width: "));
     styleValue.AppendInt(aWrapColumn);
-    styleValue.AppendWithConversion("ch;");
+    styleValue.Append(NS_LITERAL_STRING("ch;"));
   }
   else if (aWrapColumn == 0)
-    styleValue.AppendWithConversion("white-space: -moz-pre-wrap;");
+    styleValue.Append(NS_LITERAL_STRING("white-space: -moz-pre-wrap;"));
   else
-    styleValue.AppendWithConversion("white-space: pre;");
+    styleValue.Append(NS_LITERAL_STRING("white-space: pre;"));
 
   res = bodyElement->SetAttribute(styleName, styleValue);
   return res;
@@ -1637,7 +1637,7 @@ nsPlaintextEditor::PasteAsQuotation(PRInt32 aSelectionType)
 #endif
     nsAutoString flavor; flavor.AssignWithConversion(flav);
     nsAutoString stuffToPaste;
-    if (flavor.EqualsWithConversion(kUnicodeMime))
+    if (flavor.Equals(NS_LITERAL_STRING(kUnicodeMime)))
     {
       nsCOMPtr<nsISupportsWString> textDataObj ( do_QueryInterface(genericDataObj) );
       if (textDataObj && len > 0)
@@ -1776,7 +1776,7 @@ nsPlaintextEditor::Rewrap(PRBool aRespectNewlines)
   if (NS_FAILED(rv)) return rv;
 
   // Variables we'll need either way
-  nsAutoString format; format.AssignWithConversion("text/plain");
+  nsAutoString format(NS_LITERAL_STRING("text/plain"));
   nsAutoString current;
   nsString wrapped;
 
@@ -1839,7 +1839,7 @@ nsPlaintextEditor::StripCites()
   if (NS_FAILED(rv)) return rv;
 
   // Variables we'll need either way
-  nsAutoString format; format.AssignWithConversion("text/plain");
+  nsAutoString format(NS_LITERAL_STRING("text/plain"));
   nsAutoString current;
   nsString stripped;
 
diff --git a/mozilla/editor/libeditor/text/nsTextEditRules.cpp b/mozilla/editor/libeditor/text/nsTextEditRules.cpp
index 51f89b0544e..3ad06bd080d 100644
--- a/mozilla/editor/libeditor/text/nsTextEditRules.cpp
+++ b/mozilla/editor/libeditor/text/nsTextEditRules.cpp
@@ -596,7 +596,7 @@ nsTextEditRules::WillInsertText(PRInt32          aAction,
   if (NS_FAILED(res)) return res;
 
   // dont put text in places that cant have it
-  nsAutoString textTag; textTag.AssignWithConversion("__moz_text");
+  nsAutoString textTag(NS_LITERAL_STRING("__moz_text"));
   if (!mEditor->IsTextNode(selNode) && !mEditor->CanContainTag(selNode, textTag))
     return NS_ERROR_FAILURE;
 
@@ -707,7 +707,7 @@ nsTextEditRules::WillInsertText(PRInt32          aAction,
       NS_NAMED_LITERAL_STRING(tabStr, "\t");
       NS_NAMED_LITERAL_STRING(newlineStr, "\n");
       char specialChars[] = {'\t','\n',0};
-      nsAutoString tabString; tabString.AssignWithConversion("    ");
+      nsAutoString tabString(NS_LITERAL_STRING("    "));
       while (unicodeBuf && (pos != -1) && ((PRUint32)pos < tString.Length()))
       {
         PRInt32 oldPos = pos;
@@ -1038,7 +1038,7 @@ nsTextEditRules::DidRedo(nsISelection *aSelection, nsresult aResult)
       if (NS_FAILED(res)) return res;
       if (!theBody) return NS_ERROR_FAILURE;
       
-      nsAutoString tagName; tagName.AssignWithConversion("div");
+      nsAutoString tagName(NS_LITERAL_STRING("div"));
       nsCOMPtr<nsIDOMNodeList> nodeList;
       res = theBody->GetElementsByTagName(tagName, getter_AddRefs(nodeList));
       if (NS_FAILED(res)) return res;
@@ -1231,8 +1231,7 @@ nsTextEditRules::CreateBogusNodeIfNeeded(nsISelection *aSelection)
     nsCOMPtr<nsIDOMElement>brElement;
     nsCOMPtr<nsIContent> newContent;
     
-    nsString qualifiedTag;
-    qualifiedTag.AssignWithConversion("br");
+    nsString qualifiedTag(NS_LITERAL_STRING("br"));
 
     res = mEditor->CreateHTMLContent(qualifiedTag, getter_AddRefs(newContent));
     brElement = do_QueryInterface(newContent);
diff --git a/mozilla/editor/libeditor/text/nsTextEditUtils.cpp b/mozilla/editor/libeditor/text/nsTextEditUtils.cpp
index 6c0ecca00c7..170d79e235f 100644
--- a/mozilla/editor/libeditor/text/nsTextEditUtils.cpp
+++ b/mozilla/editor/libeditor/text/nsTextEditUtils.cpp
@@ -110,11 +110,11 @@ nsTextEditUtils::HasMozAttr(nsIDOMNode *node)
   nsCOMPtr<nsIDOMElement> elem = do_QueryInterface(node);
   if (elem)
   {
-    nsAutoString typeAttrName; typeAttrName.AssignWithConversion("type");
+    nsAutoString typeAttrName(NS_LITERAL_STRING("type"));
     nsAutoString typeAttrVal;
     nsresult res = elem->GetAttribute(typeAttrName, typeAttrVal);
     typeAttrVal.ToLowerCase();
-    if (NS_SUCCEEDED(res) && (typeAttrVal.EqualsWithConversion("_moz")))
+    if (NS_SUCCEEDED(res) && (typeAttrVal.Equals(NS_LITERAL_STRING("_moz"))))
       return PR_TRUE;
   }
   return PR_FALSE;