The call to GetSelection() from DoTransaction() shows up in profiles, for example see https://perfht.ml/2v729RT When we are coming from TextEditRules::WillSetText() we can easily just keep passing down the Selection& reference we have on the stack instead of paying the cost of looking it up again three frames down the call chain.

Comment on attachment 8891463 [details] [diff] [review] Avoid needlessly looking up the selection twice when DoTransaction() is called from TextEditRules::WillSetText() >diff --git a/editor/libeditor/TextEditRules.cpp b/editor/libeditor/TextEditRules.cpp >index 76f9b14ee59a..b7c2f814b030 100644 >--- a/editor/libeditor/TextEditRules.cpp >+++ b/editor/libeditor/TextEditRules.cpp >@@ -898,17 +898,17 @@ TextEditRules::WillSetText(Selection& aSelection, > > nsINode* curNode = rootElement->GetFirstChild(); > if (NS_WARN_IF(!EditorBase::IsTextNode(curNode))) { > return NS_OK; > } > > // Even if empty text, we don't remove text node and set empty text > // for performance >- nsresult rv = textEditor->SetTextImpl(tString, *curNode->GetAsText()); >+ nsresult rv = textEditor->SetTextImpl(aSelection, tString, *curNode->GetAsText()); nit: over 80 chars this line. Otherwise, looks grate!

Pushed by eakhgari@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/0ae424f348a3 Avoid needlessly looking up the selection twice when DoTransaction() is called from TextEditRules::WillSetText(); r=masayuki