[PATCH] make PIO_fdopen return NULL on incorrect flags

[Luke Palmer]

This patch makes PIO_fdopen return NULL when you give it flags it
doesn't understand.  I gathered that this was the correct behavior
from the test that I untodid.

Luke

Index: t/src/io.t
===================================================================
--- t/src/io.t	(revision 7981)
+++ t/src/io.t	(working copy)
@@ -585,8 +585,6 @@
 
 ###############################################################################
 
-SKIP: {
-    skip ("fdopen does not handle illegal modes correct", 1);
 c_output_is($main . <<'CODE', <<'OUTPUT', "PIO_fdopen");
 static opcode_t*
 the_test(Interp *interpreter,
@@ -620,7 +618,6 @@
 CODE
 done
 OUTPUT
-}
 
 ###############################################################################
 
Index: io/io.c
===================================================================
--- io/io.c	(revision 7981)
+++ io/io.c	(working copy)
@@ -730,6 +730,8 @@
     }
 
     flags = PIO_parse_open_flags(sflags);
+    if (!flags) return NULL;
+
     io = PIO_fdopen_down(interpreter, layer, fd, flags);
     /* io could be null here but we still have to
      * to create a PMC for the caller, no PMCNULL here