[Regression] Drag and drop with empty mimeData->text() occasionally.

1) Use the sample application from QTBUG-27366
2) Create 2 instances of application.
3) Drag text from instance A to instance B, repeat step 3 multiple times.

Observe that occasionally text in application B changes to "# yo" (expected is "#Drag/drop" widget yo") what is a result of mimeData->text() being empty.