Created attachment 20456 [details]
Preprocessed source of example program

Can you please provide a shorter, self-contained (no includes), testcase? Thanks in advance. CC-ing Ian...

Created attachment 20869 [details]
simpler example

Preprocessed source of simpler program.
The only #include used was <typeinfo> which is needed in order to compile with g++

Excellent, thanks a lot.

I also double checked that indeed the last "null_type" appears truncated.

Ian, any idea what may be happening here?

Non pre-processed testcase. Apparently some buffer is overflowed.

#include <cxxabi.h>

namespace abcdefgxyzzzaaaaabbbbbb
{
  class Aaa { };

  namespace klmn
  {
    class Baaaaaaaaaaaaaaa { };
  }
}

namespace boost
{
  namespace tuples
  {

    class null_type;

    template<typename T1 = null_type, typename T2 = null_type,
	     typename T3 = null_type, typename T4 = null_type,
	     typename T5 = null_type, typename T6 = null_type,
	     typename T7 = null_type, typename T8 = null_type,
	     typename T9 = null_type, typename T10 = null_type>
      struct tuple { };
  }
}

int main()
{
  int status = 0;

  const char* mangled_name
    = typeid(boost::tuples::tuple<abcdefgxyzzzaaaaabbbbbb::Aaa,
	     abcdefgxyzzzaaaaabbbbbb::klmn::Baaaaaaaaaaaaaaa>).name();

  __builtin_printf("Mangled name:\n%s\n\n", mangled_name);

  const char* dem_name = abi::__cxa_demangle(mangled_name, 0, 0, &status);

  if (0 == status)
    __builtin_printf("Demangled name:\n\n%s\n\n", dem_name);

  return 0;
}

Recategorizing as other (like 42230)... and maybe HJ is interested in playing a bit with this one too.

It is caused by revision 142799:

http://gcc.gnu.org/ml/gcc-cvs/2008-12/msg00498.html

Thanks HJ.

Can be reproduced also with
c++filt _ZN5boost6tuples5tupleIN23abcdefgxyzzzaaaaabbbbbb3AaaENS2_4klmn16BaaaaaaaaaaaaaaaENS0_9null_typeES6_S6_S6_S6_S6_S6_S6_EE

I see the bug.

Subject: Bug 43838

Author: jakub
Date: Thu Jun 10 15:15:18 2010
New Revision: 160554

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=160554
Log:
	PR other/43838
	* cp-demangle.c (struct d_print_info): Add flush_count field.
	(d_print_init): Initialize it to 0.
	(d_print_flush): Increment it.
	(d_print_comp): If needed flush before appending ", ".  Only
	decrement dpi->len if no flushes happened during the recursive
	call.
	* testsuite/demangle-expected: Add a test for this.

Modified:
    trunk/libiberty/ChangeLog
    trunk/libiberty/cp-demangle.c
    trunk/libiberty/testsuite/demangle-expected

Subject: Bug 43838

Author: jakub
Date: Thu Jun 10 15:24:11 2010
New Revision: 160555

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=160555
Log:
	PR other/43838
	* cp-demangle.c (struct d_print_info): Add flush_count field.
	(d_print_init): Initialize it to 0.
	(d_print_flush): Increment it.
	(d_print_comp): If needed flush before appending ", ".  Only
	decrement dpi->len if no flushes happened during the recursive
	call.
	* testsuite/demangle-expected: Add a test for this.

Modified:
    branches/gcc-4_5-branch/libiberty/ChangeLog
    branches/gcc-4_5-branch/libiberty/cp-demangle.c
    branches/gcc-4_5-branch/libiberty/testsuite/demangle-expected

Subject: Bug 43838

Author: jakub
Date: Thu Jun 10 15:31:56 2010
New Revision: 160556

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=160556
Log:
	PR other/43838
	* cp-demangle.c (struct d_print_info): Add flush_count field.
	(d_print_init): Initialize it to 0.
	(d_print_flush): Increment it.
	(d_print_comp): If needed flush before appending ", ".  Only
	decrement dpi->len if no flushes happened during the recursive
	call.
	* testsuite/demangle-expected: Add a test for this.

2009-06-16  Nick Clifton  <nickc@redhat.com>

	PR 10197
	* testsuite/test-demangle.c: Rename getline to get_line to avoid
	conflicts with system function of the same name.

Modified:
    branches/gcc-4_4-branch/libiberty/ChangeLog
    branches/gcc-4_4-branch/libiberty/cp-demangle.c
    branches/gcc-4_4-branch/libiberty/testsuite/demangle-expected
    branches/gcc-4_4-branch/libiberty/testsuite/test-demangle.c

Fixed.