Do not show examples that do not have a projectPath associated.

Tutorials are handled differently, these can still only have
documentation or video.

Task-number: QTBUG-28396
Change-Id: Ief79756c44633b1d105357b385595a1267f730f4
Reviewed-by: hjk <qthjk@ovi.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Reviewed-by: Christiaan Janssen <christiaan.janssen@digia.com>

src/plugins/qtsupport/exampleslistmodel.cpp

@@ -121,7 +121,7 @@ static bool isValidExampleOrDemo(ExampleItem &item)
     static QString invalidPrefix = QLatin1String("qthelp:////"); /* means that the qthelp url
                                                                     doesn't have any namespace */
     bool ok = true;
-    if (item.hasSourceCode && !QFileInfo(item.projectPath).exists())
+    if (!item.hasSourceCode || !QFileInfo(item.projectPath).exists())
         ok = false;
     else if (item.imageUrl.startsWith(invalidPrefix) || !QUrl(item.imageUrl).isValid())
         ok = false;