The diagram properties dialog showed a small sample drawing - one object type, one fact type and one label - as its preview. It was never finished, and it said nothing about the diagram actually being styled: colours, fonts and line settings could only be judged on three shapes that were not the model at hand.

The dialog now has a Preview button that applies the settings to the real diagram behind it, so a style can be judged on the model it is meant for. Previewing decides nothing: cancelling the dialog puts the diagram back the way it was, redrawn. When there is no diagram to preview on - the default diagram properties from the main menu - the button is disabled.

With the sample preview gone the dialog is a good deal smaller, so it covers less of the diagram it is now previewing on.

Two smaller things this also settles: picking a style from the Profiles menu could not be undone with Cancel, and the settings of a diagram that is viewed zoomed in are no longer at risk of coming back at the wrong font size.