Bug 1257730 - Fix ping when no URI is available. r=sicking

docshell/base/nsDocShell.cpp

@@ -375,7 +375,10 @@ ForEachPing(nsIContent* aContent, ForEachPingCallback aCallback, void* aClosure)
     ios->NewURI(NS_ConvertUTF16toUTF8(tokenizer.nextToken()),
                 doc->GetDocumentCharacterSet().get(),
                 baseURI, getter_AddRefs(uri));
-
+    // if we can't generate a valid URI, then there is nothing to do
+    if (!uri) {
+      continue;
+    }
     // Explicitly not allow loading data: URIs
     bool isDataScheme =
       (NS_SUCCEEDED(uri->SchemeIs("data", &isDataScheme)) && isDataScheme);