CSHARP-5654: String.IndexOf comparisons to -1 return incorrect results #1855
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The problem is that our code to translate
IndexOfcomparisons assumes that the comparand is greater than or equal to zero but did not enforce that.The behavior is undefined when the comparand is negative.
The short term fix is to throw an
ExpressionNotSupportedExceptionwhen the comparand is negative, which has the effect of causing the queries to be translated using$expr.Queries using
$exprare not very efficient. But with this PR at least they are correct so the bug is fixed.See CSHARP-5844 for possible future work to translate these queries using regular expressions.