Incorrect QueryExpression Rebase causes unhandled LightSpeedException

We start out by creating a QueryExpression that contains very similar attribute paths (here "string" and "System.Byte[]" are values we're querying for:

(
  Entity.Attribute("A.B.P.C.D") == string &&
  Entity.Attribute("A.B.P.C.E") < System.Byte[] &&
  Entity.Attribute("A.B.P.C.F") > System.Byte[]
) ||
(
  Entity.Attribute("A.B.Q.C.D") == string &&
  Entity.Attribute("A.B.Q.C.E") < System.Byte[] &&
  Entity.Attribute("A.B.Q.C.F") > System.Byte[]
) ||
(
  Entity.Attribute("A.B.R.C.D") == string &&
  Entity.Attribute("A.B.R.C.E") < System.Byte[] &&
  Entity.Attribute("A.B.R.C.F") > System.Byte[]
) ||
(
  Entity.Attribute("A.B.S.C.D") == string &&
  Entity.Attribute("A.B.S.C.E") < System.Byte[] &&
  Entity.Attribute("A.B.S.C.F") > System.Byte[]
) 

In QueryBuilderBase.VisitTypeModel, queryExpression is

{(
  (
    (
      ((A.B.P.C[D = string] AND A.B.P.C[E < System.Byte[]]) AND A.B.P.C[F > System.Byte[]]) OR
      ((A.B.Q.C[D = string] AND A.B.Q.C[E < System.Byte[]]) AND A.B.Q.C[F > System.Byte[]])
    ) OR
    ((A.B.R.C[D = string] AND A.B.R.C[E < System.Byte[]]) AND A.B.R.C[F > System.Byte[]])
  ) OR
  ((A.B.S.C[D = string] AND A.B.S.C[E < System.Byte[]]) AND A.B.S.C[F > System.Byte[]])
)}

and on line 473 queryExpression.Rebase is called with an empty context path, and assigned to contextExpression:

{A.B[
(
  (C[
    (C[((D = string AND E < System.Byte[]) AND F > System.Byte[])] OR
     C[((D = string AND E < System.Byte[]) AND F > System.Byte[])]
    )] OR
    R.C[((D = string AND E < System.Byte[]) AND F > System.Byte[])]
   ) OR
   S.C[((D = string AND E < System.Byte[]) AND F > System.Byte[])]
)]}

The problem is that P and Q have been removed and replaced with a combined C[...]. The B entity does not have a C, it should be B.P.C and B.Q.C. Ulitmately this throws an unhandled LightSpeedException, Path component [C] not found in type [B].

I was able to work around this by adding an extra A.B to the beginning of my the attribute paths in the second QueryExpression,

(
  Entity.Attribute("A.B.A.B.Q.C.D") == string &&
  Entity.Attribute("A.B.A.B.Q.C.E") < System.Byte[] &&
  Entity.Attribute("A.B.A.B.Q.C.F") > System.Byte[]
) ||

Apparently this is sufficient to prevent the incorrect simplification, but a correct simplification should be possible.

I ran the query with a nightly build, 2.2.20090901.

Thanks for reporting this.  I've committed a candidate fix and this will be included in nightly builds dated 22 Sept 2009 and above, available from about 1430 GMT.

Due to the complexity of your query, I have not tested this with your exact query, but only in a simplified version.  (But I did see the same bug and I don't think the additional complexity of your case alters the nature of the bug or fix, so I do believe it should work.)  Please let us know if the simplification is still incorrect in your case.

The query appears to work as expected with the fix. I haven't verified the simplification, but the evidence suggests it is correct.