Problem with URL or WebView on MacOSX

If you create a QML webview on a project MacOSX ( for example the sample minibrowser ), the way you set the URL may affect the result of the webview :

• ex 1 :
  url: "http://www.google.com"
  -> doesn't work, nothing appears, the webview remains empty

• ex 2 :
  url: { return "http://www.google.com"; }

  -> works, the webview load correctly

• ex 3 :
  url: "http://www.google.com".toString()
  -> works, the webview load correctly