Image Source control does wrong things when clicking "Cancel"

1. Open a QML file in Designer.
2. Drag an Image item onto the canvas.
   The "Source" control in Properties view displays a path ending in "template_image.png"
3. Click on the "..." button right of the "Source" control.
4. Click "Cancel".
   The path disappears.
5. Switch to Edit mode and back to Design mode.
   The path is back.

Not bad enough? It gets worse:

1. Open a QML file in Designer.
2. Drag two Image items onto the canvas.
3. Select one of the Image items.
4. Click on the "..." button, select an image file and click "OK".
   The image item displays the file.
5. Select the other Image item.
6. Click on the "..." button and click "Cancel".
   The image item displays the file from step 4.

Clicking "Cancel" should not do anything except for closing the current dialog. It should neither remove displayed paths nor should it insert images to where they don't belong.

The bug can also be reproduced with BorderImage items.