Bug 421067: 'Try Again' after a DNS error sometimes loads previous page, not the one that failed to load, patch by Michal Novotny <michal@allpeers.com>, r+sr=bzbarsky, a=schrep

docshell/base/nsDocShell.cpp

@@ -3221,11 +3221,13 @@ nsDocShell::LoadErrorPage(nsIURI *aURI, const PRUnichar *aURL,
     if (mSessionHistory && !mLSHE) {
         PRInt32 idx;
         mSessionHistory->GetRequestedIndex(&idx);
+        if (idx == -1)
+            mSessionHistory->GetIndex(&idx);
+
         nsCOMPtr<nsIHistoryEntry> entry;
         mSessionHistory->GetEntryAtIndex(idx, PR_FALSE,
                                          getter_AddRefs(entry));
         mLSHE = do_QueryInterface(entry);
-
     }
 
     nsCAutoString url;

docshell/shistory/public/nsISHistory.idl

@@ -80,7 +80,9 @@ interface nsISHistory: nsISupports
 
   /**
    * A readonly property of the interface that returns 
-   * the index of the last document that started to load.
+   * the index of the last document that started to load and
+   * didn't finished yet. When document finishes the loading
+   * value -1 is returned.
    */
    readonly attribute long requestedIndex;
 

docshell/shistory/src/nsSHistory.cpp

@@ -1054,6 +1054,7 @@ nsSHistory::UpdateIndex()
     mIndex = mRequestedIndex;
   }
 
+  mRequestedIndex = -1;
   return NS_OK;
 }