Bug 631269 - Reduce duplicate code in CloneAndReplaceChild; r=bz

docshell/base/nsDocShell.cpp

@@ -10189,7 +10189,6 @@ struct NS_STACK_CLASS CloneAndReplaceData
 nsDocShell::CloneAndReplaceChild(nsISHEntry *aEntry, nsDocShell *aShell,
                                  PRInt32 aEntryIndex, void *aData)
 {
-    nsresult result = NS_OK;
     nsCOMPtr<nsISHEntry> dest;
 
     CloneAndReplaceData *data = static_cast<CloneAndReplaceData*>(aData);
@@ -10199,55 +10198,44 @@ nsDocShell::CloneAndReplaceChild(nsISHEntry *aEntry, nsDocShell *aShell,
     nsCOMPtr<nsISHContainer> container =
       do_QueryInterface(data->destTreeParent);
     if (!aEntry) {
-      if (container) {
-        container->AddChild(nsnull, aEntryIndex);
-      }
-      return NS_OK;
+        if (container) {
+            container->AddChild(nsnull, aEntryIndex);
+        }
+        return NS_OK;
     }
     
     PRUint32 srcID;
     aEntry->GetID(&srcID);
 
+    nsresult rv = NS_OK;
     if (srcID == cloneID) {
         // Replace the entry
         dest = replaceEntry;
-        dest->SetIsSubFrame(PR_TRUE);
-
-        if (data->cloneChildren) {
-            // Walk the children
-            CloneAndReplaceData childData(cloneID, replaceEntry,
-                                          data->cloneChildren, dest);
-            result = WalkHistoryEntries(aEntry, aShell,
-                                        CloneAndReplaceChild, &childData);
-            if (NS_FAILED(result))
-                return result;
-        }
     } else {
         // Clone the SHEntry...
-        result = aEntry->Clone(getter_AddRefs(dest));
-        if (NS_FAILED(result))
-            return result;
-
-        // This entry is for a subframe navigation
-        dest->SetIsSubFrame(PR_TRUE);
+        rv = aEntry->Clone(getter_AddRefs(dest));
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+    dest->SetIsSubFrame(PR_TRUE);
 
+    if (srcID != cloneID || data->cloneChildren) {
         // Walk the children
         CloneAndReplaceData childData(cloneID, replaceEntry,
                                       data->cloneChildren, dest);
-        result = WalkHistoryEntries(aEntry, aShell,
-                                    CloneAndReplaceChild, &childData);
-        if (NS_FAILED(result))
-            return result;
+        rv = WalkHistoryEntries(aEntry, aShell,
+                                CloneAndReplaceChild, &childData);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
 
-        if (aShell)
-            aShell->SwapHistoryEntries(aEntry, dest);
+    if (srcID != cloneID && aShell) {
+        aShell->SwapHistoryEntries(aEntry, dest);
     }
 
     if (container)
         container->AddChild(dest, aEntryIndex);
 
     data->resultEntry = dest;
-    return result;
+    return rv;
 }
 
 /* static */ nsresult