[boost] Is it a bug in old version of boost?

Subject: [boost] Is it a bug in old version of boost?
From: Bill David (billdavidcn_at_[hidden])
Date: 2009-02-12 03:18:28

I have the following code in my application. But I find it causes a serious
memory leak with a product we are using. Our application is a plug-in to
this product. But we are not sure what's the boost version included by this
product.

The following is the code (On Windows, the product should be written with
Visual Studio 2003/2005):
/**
 * @brief Convert modify time string to time_t for easy internal handling
 * @param str Modify time string returned by HTTP server, e.g. "Fri, 18 Jul
2008 11:53:14 GMT"
 * @return Corresponding time_t result
 */
time_t parseDate(const string& str)
{
    ptime p;
    stringstream ss(str.c_str());
    time_input_facet* timefacet = new time_input_facet("%a, %d %b %Y
%H:%M:%S %z"); // will be automatically deleted by related locale object
    ss.imbue(locale(locale::classic(), timefacet));
    ss >> p;

    tm t = to_tm(p);
    return mktime(&t);
}

And we find the problem is caused by
time_input_facet* timefacet = new time_input_facet("%a, %d %b %Y %H:%M:%S
%z");
ss.imbue(locale(locale::classic(), timefacet));
it seems related memory has not been released by locale or some memory is
leaked by time_input_facet.

We have tested above code separately with boost 1.35.0, 1.37.0, it's OK. So
can anybody tell me if it's any problem in above code? Or is it a bug in old
version of boost date_time or MS Visual Studio 2003/2005? Or how can I work
around it?