(Merging nsbeta2 checkin to the tip) Fixing nsbeta2+ bug 28572, the docshell was fireing the script unload handler too early in some cases and in some other cases the unload handler was fired even if the document wasn't unloaded. r=nisheeth, a=nisheeth.

docshell/base/nsWebShell.cpp

@@ -382,7 +382,13 @@ nsWebShell::GetInterface(const nsIID &aIID, void** aInstancePtr)
 NS_IMETHODIMP
 nsWebShell::SetupNewViewer(nsIContentViewer* aViewer)
 {
+   NS_ENSURE_SUCCESS(FireUnloadEvent(), NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(nsDocShell::SetupNewViewer(aViewer), NS_ERROR_FAILURE);
+
+   // Set mFiredUnloadEvent = PR_FALSE so that the unload handler for the
+   // *new* document will fire.
+   mFiredUnloadEvent = PR_FALSE;
+
     // If the history state has been set by session history,
     // set it on the pres shell now that we have a content
     // viewer.
@@ -886,11 +892,6 @@ nsWebShell::OnStartDocumentLoad(nsIDocumentLoader* loader,
 
    if(loader == mDocLoader)
       {
-      //fire unload event to old doc
-      rv = FireUnloadEvent();
-      //reset mFiredUnloadEvent for the new doc
-      mFiredUnloadEvent = PR_FALSE;
-
       nsCOMPtr<nsIDocumentLoaderObserver> dlObserver;
 
       if(!mDocLoaderObserver && mParent)