new getconf shell builtin

test.c

@@ -343,11 +343,7 @@ arithcomp (s, t, op, flags)
     {
       int eflag;
 
-#if 0 /* TAG:bash-5.2 */
       eflag = (shell_compatibility_level > 51) ? 0 : EXP_EXPANDED;
-#else
-      eflag = 0;
-#endif
       l = evalexp (s, eflag, &expok);
       if (expok == 0)
 	return (FALSE);		/* should probably longjmp here */
@@ -642,11 +638,13 @@ unary_test (op, arg, flags)
 	  /* Let's assume that this has already been expanded once. */
 	  /* XXX - TAG:bash-5.2 fix with corresponding fix to execute_cmd.c:
 	     execute_cond_node() that passes TEST_ARRAYEXP in FLAGS */
-	  
+
 #if 0
 	  /* TAG:bash-5.2 */
 	  if (shell_compatibility_level > 51)
 #endif
+	    /* Allow associative arrays to use `test -v array[@]' to look for
+	       a key named `@'. */
 	    aflags |= AV_ATSTARKEYS;
 	  t = array_value (arg, 0, aflags, &rtype, (arrayind_t *)0);
 	  ret = t ? TRUE : FALSE;