Index: /trunk/boost/regex/v4/basic_regex_parser.hpp

===================================================================

--- /trunk/boost/regex/v4/basic_regex_parser.hpp (revision 38864)

+++ /trunk/boost/regex/v4/basic_regex_parser.hpp (revision 42674)

@@ -785,4 +785,5 @@

       case syntax_element_jump:

       case syntax_element_startmark:

+      case syntax_element_backstep:

          // can't legally repeat any of the above:

          fail(regex_constants::error_badrepeat, m_position - m_base);

@@ -1870,4 +1871,5 @@

    {

       re_syntax_base* b = this->getaddress(expected_alt_point);

+      // Make sure we have exactly one alternative following this state:

       if(b->type != syntax_element_alt)

       {

@@ -1878,4 +1880,13 @@

       {

          fail(regex_constants::error_bad_pattern, m_position - m_base);

+         return false;

+      }

+      // check for invalid repetition of next state:

+      b = this->getaddress(expected_alt_point);

+      b = this->getaddress(static_cast<re_alt*>(b)->next.i, b);

+      if((b->type != syntax_element_assert_backref)

+         && (b->type != syntax_element_startmark))

+      {

+         fail(regex_constants::error_badrepeat, m_position - m_base);

          return false;

       }

Index: /trunk/libs/regex/test/regress/test_perl_ex.cpp

===================================================================

--- /trunk/libs/regex/test/regress/test_perl_ex.cpp (revision 30980)

+++ /trunk/libs/regex/test/regress/test_perl_ex.cpp (revision 42674)

@@ -122,4 +122,15 @@

    TEST_INVALID_REGEX("(?:(a)|b)(?(?<", perl);

    TEST_INVALID_REGEX("(?:(a)|b)(?(?<a", perl);

+

+   TEST_INVALID_REGEX("(?(?!#?)+)", perl);

+   TEST_INVALID_REGEX("(?(?=:-){0})", perl);

+   TEST_INVALID_REGEX("(?(123){1})", perl);

+   TEST_INVALID_REGEX("(?(?<=A)*)", perl);

+   TEST_INVALID_REGEX("(?(?<=A)+)", perl);

+

+   TEST_INVALID_REGEX("(?<!*|^)", perl);

+   TEST_INVALID_REGEX("(?<!*|A)", perl);

+   TEST_INVALID_REGEX("(?<=?|A)", perl);

+   TEST_INVALID_REGEX("(?<=*|\\B)", perl);

 }