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Call to the regex_match(chkString,Match,Expression,match_not_dot_newline) causes program go into an infinite loop when chkString="http://localhost/ideas/exchange/June98/test/test.cfm" and Expression="^/(.*)*.cfm" Both Regex++ and test program are compiled with VC7.0 on WindowsXP. I have tried to play with optimisation settings, but this >bug appears even in debug configuration. I understand that syntax of regular expression is incorrect, but library should rise error in >this case. I hope that I'm doing something wrong and there is a workaround to this problem.

anything that contains (.*)* is going to get pathological: it's the classic test case that breaks all backtracking regex implementations. I hope that a future version will detect and throw and exception when something like

"John Maddock" wrote in message news:00c301c257f1$7f873f20$e65587d9@1016031671... this

is used.

The "(.*)*" is strange ( zero or more of any character, except newline in the case above, repeated zero or more times ) but is shouldn't cause an infinite loop if that is what it is acrually doing. If it does, I think it needs to be fixed in a future release.

Hello, John! You wrote on Mon, 9 Sep 2002 12:09:37 +0100: JM> anything that contains (.*)* is going to get pathological: it's the JM> classic test case that breaks all backtracking regex implementations. JM> I hope that a future version will detect and throw and exception when JM> something like this is used. I hope so. But now we have added timer to the regex_match algorithm, so now it throws exception on timeout. This slows down algorithm, but we need this protection. Also I have found that older versions of Regex++ don't have this vulnerability. Maybe there is a way to find if regular expression contains nested repeats on creation stage? With best regards, Yaroslav Govorunov, E-mail: slov@rsdn.ru http://www.rsdn.ru http://www.isapirewrite.com