Bug 389870 - When previous action was to use a local helper app, the protocol never works again. r=cbiesinger, sr=dmose, a=schrep

uriloader/exthandler/nsExternalProtocolHandler.cpp

@@ -343,14 +343,26 @@ NS_IMETHODIMP nsExtProtocolChannel::AsyncOpen(nsIStreamListener *listener, nsISu
   nsCOMPtr<nsIHandlerInfo> handlerInfo;
   rv = gExtProtSvc->GetProtocolHandlerInfo(urlScheme, 
                                            getter_AddRefs(handlerInfo));
+  // TODO all this code should be moved to nsIHandlerInfo::LaunchWithURI
   if (NS_SUCCEEDED(rv)) {
     PRInt32 preferredAction;                                           
     rv = handlerInfo->GetPreferredAction(&preferredAction);
 
-    // for now, anything that triggers a helper app is going to be a web-based
-    // protocol handler, so we use that to decide which path to take...
     if (preferredAction == nsIHandlerInfo::useHelperApp) {
 
+      nsCOMPtr<nsIHandlerApp> handler;
+      rv = handlerInfo->GetPreferredApplicationHandler(getter_AddRefs(handler));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Now we check to see if this is a local handler or not
+      nsCOMPtr<nsILocalHandlerApp> localHandler =
+        do_QueryInterface(handler, &rv);
+      if (NS_SUCCEEDED(rv)) {
+        OpenURL();
+        return NS_ERROR_NO_CONTENT; // force caller to abort
+      }
+
+      // We must have a web handler
       // redirecting to the web handler involves calling OnChannelRedirect
       // (which is supposed to happen after AsyncOpen completes) or possibly
       // opening a dialog, so we do it in an event