[boost] [regex] Thread safety patch

From: John Maddock (john_at_[hidden])
Date: 2006-07-29 12:08:42

With apologies to all concerned, and thanks to Aleksey Sanin for tracking 
down the problem, there is a const-correctness bug in Boost.Regex-1.33.x 
that strikes only in multithreaded programs on Unix platforms, if:

* Multiple threads construct regexes concurrently, or
* Multiple threads perform search and replace operations concurrently.

There are two possible fixes:

* Apply the attached patch (this has just gone into cvs along with an 
updated test case that detects the issue). Or,
* define BOOST_REGEX_USE_C_LOCALE in boost/user.hpp and rebuild everything.

Regards, John Maddock.