Watchdog model fails on if-equations

[Per Östlund]

The attached model gives the following error message:

true
record SimulationResult
    resultFile = "Simulation failed.
Error: The language feature if-equations is not supported. Suggested workaround: rewrite equations using if-expressions: equation
  if dm.watch_dog.battery_level > 0.0 then
  if dm.watch_dog.Operation_Modes.Region_0.Active.active OR dm.watch_dog.Operation_Modes.Region_0.Alarmed.active then
  der(dm.watch_dog.battery_level) = -1.0;
  else
  der(dm.watch_dog.battery_level) = 0.0;
  end if;
  else
  der(dm.watch_dog.battery_level) = 0.0;
  end if;

"
end SimulationResult;

If equations does normally work, since they are automatically rewritten to if-expressions, but in this case that seems to fail. The attached zip-file includes the model itself as well as a Word document that shows the settings and output in MathModelica.

[Per Östlund]

Watchdog model

[AlexeyLebedev]

The bug was caused by if-equation having another if-equation in one of the branches. I have implemented translation of such if-equations to normal equations with if-expressions in revision 5572.

Also, such equations could have wrong equation count. For example, the following equation:
{{{ if bool then

if z>0 then

x=z;
y=z;

else

x=-z;
y=-z;

end if;

else

x=0;
y=0;

end if;}}}

would be considered to have 1 equation in true branch and 2 equations in false branch. I have fixed this, also.

[AlexeyLebedev]

Added a testcase (mosfiles/IfEquation3.mos)