So, there's a weird int_of_string bug where positive decimal numbers are sometimes read in as negative numbers without error.  Here's the bug:

http://caml.inria.fr/mantis/view.php?id=0004210

This has been marked as "wontfix" in the bug database because apparently there's some weird spot in the lexer that depends on the wrong behavior of int_of_string. 

First of all, people should be aware of this behavior and should defend against it in their code.  Secondly, the justification for not fixing it seems really thin.  The behavior seems obviously wrong, and it's hard to see why one wouldn't simply fix the lexer (perhaps by providing an alternate broken implementation of int_of_string) and leave the ordinary int_of_string where it is.

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