id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
2157,Xpressive end-of-line match broken,Simon Steele <s.steele@…>,Eric Niebler,"End of line matching inside a string is broken, simple example:

Subject: abc\ndef\nghi
Regex: ^.+$

I'm looking for ""abc"". The following xpressive-based code has odd results:

string text(argv[1]);
sregex rex = sregex::compile(text, regex_constants::not_dot_newline);

smatch match;
string subject(""abc\ndef\nghi"");
if (regex_search(subject.begin(), subject.end(), match, rex, regex_constants::match_default))
{
   std::cout << ""Match at: "" << match.position(0) << "" length: "" << match.length(0);
}

^.+$: Match at: 8 length: 3
$: Match at: 4 length: 0
.$: Match at: 10 length: 1

These definitely aren't right, it appears that the only place where
end-of-line is matching is at end-of-string. Things get even stranger if I try to use Windows or Mac style end-of-line styles. If I use boost::regex instead then I get these results:

^.+$: Match at: 0 length: 3
$: Match at: 3 length: 0
.$: Match at: 2 length: 1

These are the results I'd expect. It appears in Xpressive that the
check in assert_line_base::is_line_break is broken, the following
line:

if(traits_cast<Traits>(state).isctype(ch, this->newline_))

checks the previous character to see if it's a line break. I believe
this should check the current character:

if(traits_cast<Traits>(state).isctype(*state.cur_, this->newline_))

This then gets me sane results:

^.+$: Match at: 0 length: 3
$: Match at: 3 length: 0
.$: Match at: 2 length: 1

[note: Eric says that this patch is probably not correct as it causes regression failures]",Bugs,closed,Boost 1.36.0,xpressive,Boost 1.35.0,Problem,fixed,,