compiler crash on using namespace directive w/unknown namespace

[scott snyder]

hi -

For egcs 2.91.16, checked out on the afternoon of Mar. 31, on a
mips-sgi-irix6.2 platform, the following input crashes the compiler:

-- bug33.cc -----------------------------------------
using namespace rel_ops;
-----------------------------------------------------

% cc1plus bug33.cc
bug33.cc:1: Internal compiler error.
bug33.cc:1: Please submit a full bug report to `egcs-bugs@cygnus.com'.


It's dying in a call to do_using_directive with a null argument:

Program received signal SIGSEGV, Segmentation fault.
do_using_directive (namespace=0x0) at ../../../../egcs/gcc/cp/decl2.c:3945
3945      if (TREE_CODE (namespace) == SCOPE_REF)
(gdb) where
#0  do_using_directive (namespace=0x0) at ../../../../egcs/gcc/cp/decl2.c:3945
#1  0x1007eab0 in yyparse () at parse.y:423
#2  0x100bd040 in compile_file (name=0x7fff304d "bug33.cc")
    at ../../../egcs/gcc/toplev.c:2525
#3  0x100c07c8 in main (argc=2, argv=0x13a, envp=0x1c)
    at ../../../egcs/gcc/toplev.c:4330


thanks,
sss