#1873 locks up after vertical marker added

[JAMES SAULNIER]

See video for sequence.
Once the Wait window occurs it will toggle between that and the blue circling cursor.

[JAMES SAULNIER]

Minsky file

[High Performance Coder]

Reproduced locally on Linux. Note vertical markers work on other models, just this one hangs. Running it under a symbolic debugger didn't elucidate anything.
Possibly it is connected with both a horizontal and vertical marker coming from the same source.

[High Performance Coder]

I think the issue is the sheer magnitude of the vertical marker, coupled with autoscaling, which causes the plotting widget to go into a seemingly endless loop of 10's of millions of horizontal tick marks.

[High Performance Coder]

OK solved the problem by skipping over (ie ignoring) markers that lie outside the plot bounds.