Merge pull request #4047 from SciML/as/alias-elim-bad

fix: avoid false positives in consistency check

Author: ChrisRackauckas

src/systems/systemstructure.jl

@@ -1009,12 +1009,12 @@ function _mtkcompile!(state::TearingState;
     state = ModelingToolkit.inputs_to_parameters!(state, discrete_inputs)
     ModelingToolkit.markio!(state, Set(), inputs, outputs, disturbance_inputs)
     state = ModelingToolkit.inputs_to_parameters!(state, [inputs; disturbance_inputs])
-    trivial_tearing!(state)
-    sys, mm = ModelingToolkit.alias_elimination!(state; fully_determined, kwargs...)
     if check_consistency
         fully_determined = ModelingToolkit.check_consistency(
             state, orig_inputs; nothrow = fully_determined === nothing)
     end
+    trivial_tearing!(state)
+    sys, mm = ModelingToolkit.alias_elimination!(state; fully_determined, kwargs...)
     if fully_determined && dummy_derivative
         sys = ModelingToolkit.dummy_derivative(
             sys, state; mm, check_consistency, kwargs...)

test/stream_connectors.jl

@@ -494,7 +494,8 @@ function OneFluidSystem(; name)
            connect(source_a.H, pipe_a.HA)
            connect(pipe_a.HB, volume_a.H)
            connect(source_b.H, pipe_b.HA)
-           connect(pipe_b.HB, volume_b.H)]
+           connect(pipe_b.HB, volume_b.H)
+           source_a.H.dm ~ 0]
 
     System(eqs, t, vars, pars; name, systems)
 end