I wrote up a schema that defines a sequence of a recurring string element. This string element has inputValueCalc set on it. It causes the following error:

[error] Test edu.illinois.ncsa.daffodil.section23.dfdl_expressions.TestDFDLExpressions.test_empty_05 failed: edu.illinois.ncsa.daffodil.exceptions.Abort: Invariant broken.
[error] edu.illinois.ncsa.daffodil.exceptions.Assert$.abort(Assert.scala:95)
[error] edu.illinois.ncsa.daffodil.exceptions.Assert$.invariant(Assert.scala:123)

See test empty_05 in the following files:
scala-debug/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/TestDFDLExpressionsDebug.scala
scala/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/TestDFDLExpressions.scala
daffodil-test/src/test/resources/edu/illinois/ncsa/daffodil/section23/dfdl_functions/Functions.tdml