wxMathPlot confused by spurious wxEVT_LEFT_UP event

[DRNadler]

Background
WxWidgets (many versions including to latest as of 15-July-2025) has a bug that sometimes generates a spurious wxEVT_LEFT_UP event after a double-click. When you have a dialog that is completed by a double-click (ie, you double-click on a filename in a wxFileDialog, or you double-click on a list entry in your own dialog), the dialog closes just fine after completing the double-click processing. Unfortunately, the spurious wxEVT_LEFT_UP event is sent to what-ever window was in back of the double-click position. The foreground dialog is already gone when the event shows up for wxWidgets - so wxWidgets just routes it to the top-most window at the click position...

See for example:
Dave's summary wxWidgets Issue
wxWidgets/issues/25446
wxWidgets/issues/10924
Incomplete fix attempt

wxMathPlot Problem
The spurious wxEVT_LEFT_UP causes bad ZoomRect to strange size in mpWindow::OnMouseLeftRelease(wxMouseEvent &event)
It looks like wxMathPlot has lost its mind when this happens.

So, what is a sensible way to handle this in wxMathPlot?
It's unfortunate that this is not fixed inside wxWidgets event processing, aarrrgggg....
Basically a left-up event should only be allowed after a left-down (and not after a left-down and mouse-leaves-window, etc).

[GitHubLionel]

Hi Dave,

I am not able to reproduce the problem (no program with this situation).
If it is a wxWidgets problem, it should be solve at this level.
You can maybe test a workaround in wxMathPlot by using the OnUserMouseAction function.
Something like (not tested):

void MyFrame::OnUserMouseAction(void *Sender, wxMouseEvent &event, bool &cancel)
{
  static bool isLeftDown = false;
  cancel = false; // Continue the standard operation
  
  // Left mouse button down
  if (event.LeftDown())
  {
    // Start left down operation
    isLeftDown = true;
  }
  else
    if (event.LeftUp())
    {
      // If left up event is coming without left down event, we cancel the standard operation
      cancel = !isLeftDown;
      isLeftDown = false; // Eat the boolean
    }
    // for other events, I don't know ...

}

[DRNadler]

Any dialog with for example a listbox taking a double-click selection that closes the dialog will reproduce the problem...