[DAFFODIL-1221] Abort: Invariant Broken when XPath expression moves past root

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.0
• Fix Version/s: 2.3.0
• Component/s: General
• Assignee: Dave Thompson
• Reporter: Jessie Chab
• Created: 04/Feb/15 15:06
• Updated: 20/May/21 12:34
• Resolved: 07/Sep/18 14:37

Description

If the XPath expression extends beyond the root of the tree, you get the following error:

[error] Test edu.illinois.ncsa.daffodil.section23.dfdl_expressions.TestDFDLExpressions.test_beyondRoot_01 failed: edu.illinois.ncsa.daffodil.exceptions.Abort: Invariant broken. UpMove past root. Should never happen since an expression like that won't typecheck statically.
[error] edu.illinois.ncsa.daffodil.exceptions.Assert$.abort(Assert.scala:95)
[error] edu.illinois.ncsa.daffodil.exceptions.Assert$.invariantFailed(Assert.scala:136)
[error] edu.illinois.ncsa.daffodil.dpath.UpMove$$anonfun$1.apply(UpDownMoves.scala:32)
[error] edu.illinois.ncsa.daffodil.dpath.UpMove$$anonfun$1.apply(UpDownMoves.scala:32)
[error]     at edu.illinois.ncsa.daffodil.exceptions.Assert$.abort(Assert.scala:95)
[error]     at edu.illinois.ncsa.daffodil.exceptions.Assert$.invariantFailed(Assert.scala:136)
[error]     at edu.illinois.ncsa.daffodil.dpath.UpMove$$anonfun$1.apply(UpDownMoves.scala:32)
[error]     at edu.illinois.ncsa.daffodil.dpath.UpMove$$anonfun$1.apply(UpDownMoves.scala:32)
[error]     at edu.illinois.ncsa.daffodil.util.Maybe$.getOrElse$extension(Maybe.scala:30)
[error]     at edu.illinois.ncsa.daffodil.dpath.UpMove$.run(UpDownMoves.scala:32)
[error]     at edu.illinois.ncsa.daffodil.dpath.CompiledDPath.run(DPathRuntime.scala:85)
[error]     at edu.illinois.ncsa.daffodil.dpath.CompiledDPath.runExpression(DPathRuntime.scala:31)
[error]     at edu.illinois.ncsa.daffodil.dpath.RuntimeExpressionDPath.liftedTree1$1(DPath.scala:92)
[error]     at edu.illinois.ncsa.daffodil.dpath.RuntimeExpressionDPath.evaluate(DPath.scala:91)
[error]     at edu.illinois.ncsa.daffodil.processors.parsers.ExpressionEvaluationParser.eval(ExpressionEvaluatingParsers.scala:30)
[error]     at edu.illinois.ncsa.daffodil.processors.parsers.IVCParser$$anonfun$parse$1.apply(ExpressionEvaluatingParsers.scala:44)
[error]     at edu.illinois.ncsa.daffodil.processors.parsers.IVCParser$$anonfun$parse$1.apply(ExpressionEvaluatingParsers.scala:41)
[error]     at edu.illinois.ncsa.daffodil.processors.WithParseErrorThrowing$class.withParseErrorThrowing(ParseErrors.scala:205)
[error]     at edu.illinois.ncsa.daffodil.processors.parsers.ExpressionEvaluationParser.withParseErrorThrowing(ExpressionEvaluatingParsers.scala:19)
[error]     at edu.illinois.ncsa.daffodil.processors.parsers.IVCParser.parse(ExpressionEvaluatingParsers.scala:41)
....

I first noticed this with the interactive debugger, but have written a TDML test to demonstrate the issue:

test_beyondRoot_01

daffodil-test/src/test/resources/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/expressions.tdml
daffodil-test/src/test/scala-debug/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/TestDFDLExpressionsDebug.scala
daffodil-test/src/test/scala/edu/illinois/ncsa/daffodil/section23/dfdl_expressions/TestDFDLExpressions.scala