Melchior FRANZ:

Melchior FRANZ:

showDialog() is careful not to create a new FGDialog() if a dialog with the
same name is already open (active). But at this point it is already too late:
newDialog(), which was called shortly before, has already overwritten the
dialog properties. This leads to animated garbage in the best case, and a
segfault in format_callback() in the worst case.

- GUI::newDialog(): Don't you overwrite properties of an active dialog!
- GUI::readDir(): You may do that, but delete the old dialog first!
  (necessary for reloading the GUI)

- FGDialog::makeObject(): only set format_callback() with setRenderCallback()
  if the property is "live". Otherwise, only call it once at construction
  time. This isn't only a performance improvement. Without this the label
  was growing until it hit the limit (256).