id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
6955	Spirit parse_nan() may dereference end iterator	michael.douglas.schmidt@…	Joel de Guzman	"The function `parse_nan(first, last)` will dereference the end iterator when parsing the string ""nan"", which may lead to undefined behavior.
{{{
File: boost/spirit/home/qi/numeric/real_policies.hpp
Line: 119
}}}

This occurs for instance using the following parser:
{{{
std::string s = ""nan"";
auto s_begin = s.begin();
auto s_end   = s.end();
double out;
qi::phrase_parse(s_begin, s_end, qi::double_, ascii::space, out);
}}}

The problem occurs in parse_nan():
{{{
117: if (detail::string_parse(""nan"", ""NAN"", first, last, unused))
118: {
119:     if (*first == '(')
}}}

Line 119 should check if `first == last` first since `detail::string_parse()` may increment `first`.

"	Bugs	closed	To Be Determined	spirit	Boost 1.49.0	Problem	fixed	nan