Long "in" lists in queries results in a Java stack overflow exception.

With Hibernate 320ga a long "in" list can result in a stack overflow error during the parsing stage. For example, a query element like

where x in (:x)

or a manually constructed

where x in (1,2,3 .....)

can generate a stack overflow if the number of elements referenced by x exceeds a number dependent upon the amount of available stack space. For many JVMs, the limit is between 9,000 and 10,000 assuming a relatively empty stack at the point of query execution. We have applications which occasionally use lists several times this size.

The stack overflow occurs in org.hibernate.hql.ast.util.NodeTraverser which uses a recursive algorithm to walk a parse tree. Long "in" lists generate a subtree of depth about equal to the number of elements in the list. A sufficiently long list results in a stack overflow when NodeTraverser's internal method visitDepthFirst calls itself too many times.

The solution is to replace the recursive tree walking strategy with an iterative one that does not use up stack space. I am attaching the source for a replacement version of . NodeTraverser which implements the iterative tree walking method.