Per Mike: Probably we are not copying the stack of escape schemes when we copy the state to suspend/resume unparser work. The array index out of bounds is an empty stack....

Error:
[error] Test edu.illinois.ncsa.daffodil.section23.dfdl_expressions.TestOutputValueCalcDebug.test_ovc_w_runtime_escape_char failed: java.lang.ArrayIndexOutOfBoundsException: -1
[error] at scala.runtime.ScalaRunTime$.array_apply(ScalaRunTime.scala:73)
[error] at edu.illinois.ncsa.daffodil.util.MStack.top(MStack.scala:263)

See test test_ovc_w_runtime_escape_char in:
daffodil-test/src/test/resources/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/outputValueCalc.tdml
daffodil-test/src/test/scala-debug/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/TestOutputValueCalcDebug.scala