[hubertus65]

Adds ImpactFailures.ComplexIfExpressionInConnectorEquation, a minimal model with MSL 4.1.0 that fails in Modelon Impact (impact.modelon.cloud, checked 2026-10-31).

Failure: the generated C code does not compile. The record constructor of the connector
type leaks into the C source:

sources/..._equ.c: In function 'model_ode_derivatives_base':
error: 'Modelica' undeclared (first use in this function)
  _temp_..._13 = COND_EXP_EQ(_g_useConjugateInput_6, JMI_TRUE,
      (Modelica.ComplexBlocks.Interfaces.ComplexOutput(_g_u_re_7, - _g_u_im_8)).re, _g_u_re_7);

Trigger: a Complex if-expression written inline in the equation of a
ComplexOutput connector:

• y = k*(if useConjugateInput then Modelica.ComplexMath.conj(u) else u) in ComplexMath.Gain, and likewise in Feedback, Division and Add3
• y = offset + (if time < startTime then Complex(0) else height) in Sources.ComplexStep

Each block alone reproduces it, and so do local copies of the blocks. Assigning the if-expression to a
protected Complex variable first compiles and simulates. ComplexMath.Add and Product already
do this through u1Internal/u2Internal of Interfaces.ComplexSI2SO.

Workaround in the MSL: modelica#4847 uses intermediate variables in
the five blocks. OpenModelica results are bit-identical.

Upstream MSL pull request: modelica#4847

🤖 Generated with Claude Code

https://claude.ai/code/session_01UmNZkRw6HV9CeBvNk36AzT