[PATCH] on VMS, always exit with failure in my_failure_exit

[Craig A. Berry]

In the VMS-specific bits of perl.c:Perl_my_failure_exit, the exit status
was only being set when errno and/or vaxc$errno were non-zero. If both
were zero, Perl would exit with a success status. This has been causing
the following three tests in bleadperl to fail:

t/op/tie.............................FAILED at test 21
ext/Filter/t/call....................FAILED at test 1
lib/strict...........................FAILED at test 112

What is really bizarre is that the code in question does not appear to
have been touched in years. Either the test suite finally exposed a long
unnoticed problem, or it is a relatively new thing to be calling
Perl_my_failure_exit under conditions that do not set errno.

The attached patch expands the circumstances under which the generic
failure status SS$_ABORT will be used to include the case of errno being
zero. This tracks the behavior of the non-VMS code path, where 255 will
be used when errno is not set. After the patch, the three tests above pass.

--- perl.c;-0   Mon May 31 17:44:29 2004
+++ perl.c      Tue Jun  1 19:44:23 2004
@@ -4616,7 +4616,7 @@ Perl_my_failure_exit(pTHX)
            STATUS_NATIVE_SET(44);
     }
     else {
-       if (!vaxc$errno && errno)       /* unlikely */
+       if (!vaxc$errno)                /* unlikely */
            STATUS_NATIVE_SET(44);
        else
            STATUS_NATIVE_SET(vaxc$errno);