More perlio ->Open paranoia. Set errno to EINVAL if there's

no ->Open, not if ->Open returns NULL.

p4raw-id: //depot/perl@19749

1 files changed, 11 insertions, 9 deletions

diff --git a/perlio.c b/perlio.c
index 38db370b62..78b2d18be5 100644
--- a/perlio.c
+++ b/perlio.c
@@ -3405,9 +3405,12 @@ PerlIOBuf_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers,
 {
     if (PerlIOValid(f)) {
 	PerlIO *next = PerlIONext(f);
-	PerlIO_funcs *tab =  PerlIO_layer_fetch(aTHX_ layers, n - 1, PerlIOBase(next)->tab);
-	next = (*tab->Open) (aTHX_ tab, layers, n - 1, mode, fd, imode, perm,
-			  next, narg, args);
+	PerlIO_funcs *tab =
+	     PerlIO_layer_fetch(aTHX_ layers, n - 1, PerlIOBase(next)->tab);
+	if (tab && tab->Open)
+	     next =
+		  (*tab->Open)(aTHX_ tab, layers, n - 1, mode, fd, imode, perm,
+			       next, narg, args);
 	if (!next || (*PerlIOBase(f)->tab->Pushed) (aTHX_ f, mode, PerlIOArg, self) != 0) {
 	    return NULL;
 	}
@@ -3421,10 +3424,11 @@ PerlIOBuf_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers,
 	     * mode++;
 	     */
 	}
-	f = tab && tab->Open ?
-	  (*tab->Open) (aTHX_ tab, layers, n - 1, mode, fd, imode, perm,
-			f, narg, args)
-	  : Nullfp;
+	if (tab && tab->Open)
+	     f = (*tab->Open)(aTHX_ tab, layers, n - 1, mode, fd, imode, perm,
+			      f, narg, args);
+	else
+	     SETERRNO(EINVAL, LIB_INVARG);
 	if (f) {
 	    if (PerlIO_push(aTHX_ f, self, mode, PerlIOArg) == 0) {
 		/*
@@ -3453,8 +3457,6 @@ PerlIOBuf_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers,
 #endif
 	    }
 	}
-	else
-	    SETERRNO(EINVAL, SS_IVCHAN);
     }
     return f;
 }