Super super simplify.

include/boost/regex/v5/perl_matcher_non_recursive.hpp

@@ -1204,10 +1204,7 @@ bool perl_matcher<BidiIterator, Allocator, traits>::skip_until_paren(int index,
       else if(pstate->type == syntax_element_startmark)
       {
          int idx = static_cast<const re_brace*>(pstate)->index;
-         if(idx > 0)
-            match_startmark();
-         else
-            pstate = pstate->next.p;
+         pstate = pstate->next.p;
          skip_until_paren(idx, false);
          continue;
       }

test/Jamfile.v2

@@ -135,4 +135,3 @@ compile test_windows_defs_3.cpp ;
 compile test_windows_defs_4.cpp ;
 
 run issue153.cpp : : : "<toolset>msvc:<linkflags>-STACK:2097152" ;
-run issue227.cpp ;

test/issue227.cpp

@@ -1,19 +0,0 @@
-/*
-* Copyright (c) 2024
-* Christian Mazakas
-*
-* Use, modification and distribution are subject to the
-* Boost Software License, Version 1.0. (See accompanying file
-* LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-*
-*/
-
-#include <boost/regex.hpp>
-#include <string>
-
-int main() {
-   boost::regex rx("(*ACCEPT)*+\\1((*ACCEPT)*+\\K)");
-   std::string str = "Z";
-   boost::smatch what;
-   boost::regex_search(str, what, rx, boost::match_default | boost::match_partial);
-}