X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=perlio.c;h=0fca6701a96f1a643cf3647cea9d7e3634b535fe;hb=53df3d8cb98cbfbef669eddaaa174212d27bd68c;hp=edfdf17a5eadc08a01b905ca1f7b04f32e34be10;hpb=a33cf58c90e96ed3c4b1c1fdbaf666d924440940;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/perlio.c b/perlio.c
index edfdf17..0fca670 100644
--- a/perlio.c
+++ b/perlio.c
@@ -214,7 +214,7 @@ PerlIO_fdupopen(pTHX_ PerlIO *f, CLONE_PARAMS *param, int flags)
 	return NULL;
     }
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
     }
 #endif
     return NULL;
@@ -337,12 +337,13 @@ PerlIO_init(pTHX)
     sfset(sfstdout, SF_SHARE, 0);
 }
 
+/* This is not the reverse of PerlIO_exportFILE(), PerlIO_releaseFILE() is. */
 PerlIO *
 PerlIO_importFILE(FILE *stdio, const char *mode)
 {
     int fd = fileno(stdio);
     if (!mode || !*mode) {
-	mmode = "r+";
+	mode = "r+";
     }
     return PerlIO_fdopen(fd, mode);
 }
@@ -480,7 +481,7 @@ PerlIO_fdupopen(pTHX_ PerlIO *f, CLONE_PARAMS *param, int flags)
 	return new;
     }
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return NULL;
     }
 }
@@ -811,7 +812,7 @@ PerlIO_parse_layers(pTHX_ PerlIO_list_t *av, const char *names)
 			Perl_warner(aTHX_ packWARN(WARN_LAYER),
 			      "perlio: invalid separator character %c%c%c in layer specification list %s",
 			      q, *s, q, s);
-		    SETERRNO(EINVAL, LIB$_INVARG);
+		    SETERRNO(EINVAL, LIB_INVARG);
 		    return -1;
 		}
 		do {
@@ -915,6 +916,46 @@ PerlIO_layer_fetch(pTHX_ PerlIO_list_t *av, IV n, PerlIO_funcs *def)
     return def;
 }
 
+IV
+PerlIOPop_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
+{
+    if (PerlIOValid(f)) {
+	PerlIO_flush(f);
+	PerlIO_pop(aTHX_ f);
+	return 0;
+    }
+    return -1;
+}
+
+PerlIO_funcs PerlIO_remove = {
+    sizeof(PerlIO_funcs),
+    "pop",
+    0,
+    PERLIO_K_DUMMY | PERLIO_K_UTF8,
+    PerlIOPop_pushed,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,                       /* flush */
+    NULL,                       /* fill */
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,                       /* get_base */
+    NULL,                       /* get_bufsiz */
+    NULL,                       /* get_ptr */
+    NULL,                       /* get_cnt */
+    NULL,                       /* set_ptrcnt */
+};
+
 PerlIO_list_t *
 PerlIO_default_layers(pTHX)
 {
@@ -937,6 +978,7 @@ PerlIO_default_layers(pTHX)
 	PerlIO_define_layer(aTHX_ & PerlIO_mmap);
 #endif
 	PerlIO_define_layer(aTHX_ & PerlIO_utf8);
+	PerlIO_define_layer(aTHX_ & PerlIO_remove);
 	PerlIO_define_layer(aTHX_ & PerlIO_byte);
 	PerlIO_list_push(aTHX_ PL_def_layerlist,
 			 PerlIO_find_layer(aTHX_ osLayer->name, 0, 0),
@@ -990,17 +1032,35 @@ PerlIO_stdstreams(pTHX)
 PerlIO *
 PerlIO_push(pTHX_ PerlIO *f, PerlIO_funcs *tab, const char *mode, SV *arg)
 {
-    PerlIOl *l = NULL;
-    Newc('L',l,tab->size,char,PerlIOl);
-    if (l && f) {
-	Zero(l, tab->size, char);
-	l->next = *f;
-	l->tab = tab;
-	*f = l;
+    if (tab->fsize != sizeof(PerlIO_funcs)) {
+      mismatch:
+	Perl_croak(aTHX_ "Layer does not match this perl");
+    }
+    if (tab->size) {
+	PerlIOl *l = NULL;
+	if (tab->size < sizeof(PerlIOl)) {
+	    goto mismatch;
+	}
+	/* Real layer with a data area */
+	Newc('L',l,tab->size,char,PerlIOl);
+	if (l && f) {
+	    Zero(l, tab->size, char);
+	    l->next = *f;
+	    l->tab = tab;
+	    *f = l;
+	    PerlIO_debug("PerlIO_push f=%p %s %s %p\n", (void*)f, tab->name,
+			(mode) ? mode : "(Null)", (void*)arg);
+	    if ((*l->tab->Pushed) (aTHX_ f, mode, arg, tab) != 0) {
+		PerlIO_pop(aTHX_ f);
+		return NULL;
+	    }
+	}
+    }
+    else if (f) {
+	/* Pseudo-layer where push does its own stack adjust */
 	PerlIO_debug("PerlIO_push f=%p %s %s %p\n", (void*)f, tab->name,
 		     (mode) ? mode : "(Null)", (void*)arg);
-	if ((*l->tab->Pushed) (aTHX_ f, mode, arg) != 0) {
-	    PerlIO_pop(aTHX_ f);
+	if ((*tab->Pushed) (aTHX_ f, mode, arg, tab) != 0) {
 	    return NULL;
 	}
     }
@@ -1008,18 +1068,6 @@ PerlIO_push(pTHX_ PerlIO *f, PerlIO_funcs *tab, const char *mode, SV *arg)
 }
 
 IV
-PerlIOPop_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
-{
-    PerlIO_pop(aTHX_ f);
-    if (*f) {
-	PerlIO_flush(f);
-	PerlIO_pop(aTHX_ f);
-	return 0;
-    }
-    return -1;
-}
-
-IV
 PerlIOBase_binmode(pTHX_ PerlIO *f)
 {
    if (PerlIOValid(f)) {
@@ -1038,13 +1086,12 @@ PerlIOBase_binmode(pTHX_ PerlIO *f)
 }
 
 IV
-PerlIORaw_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
+PerlIORaw_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
 {
 
     if (PerlIOValid(f)) {
 	PerlIO *t;
 	PerlIOl *l;
-	PerlIO_pop(aTHX_ f);     /* Remove the dummy layer */
 	PerlIO_flush(f);
 	/*
 	 * Strip all layers that are not suitable for a raw stream
@@ -1176,7 +1223,7 @@ PerlIO__close(pTHX_ PerlIO *f)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Close) (aTHX_ f);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1200,7 +1247,7 @@ Perl_PerlIO_fileno(pTHX_ PerlIO *f)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Fileno) (aTHX_ f);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1238,7 +1285,7 @@ PerlIO_layer_from_ref(pTHX_ SV *sv)
      * For any scalar type load the handler which is bundled with perl
      */
     if (SvTYPE(sv) < SVt_PVAV)
-	return PerlIO_find_layer(aTHX_ "Scalar", 6, 1);
+	return PerlIO_find_layer(aTHX_ "scalar", 6, 1);
 
     /*
      * For other types allow if layer is known but don't try and load it
@@ -1278,7 +1325,7 @@ PerlIO_resolve_layers(pTHX_ const char *layers,
 		incdef = 0;
 	    }
 	    /*
-	     * Don't fail if handler cannot be found :Via(...) etc. may do
+	     * Don't fail if handler cannot be found :via(...) etc. may do
 	     * something sensible else we will just stringfy and open
 	     * resulting string.
 	     */
@@ -1401,7 +1448,7 @@ Perl_PerlIO_read(pTHX_ PerlIO *f, void *vbuf, Size_t count)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Read) (aTHX_ f, vbuf, count);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1412,7 +1459,7 @@ Perl_PerlIO_unread(pTHX_ PerlIO *f, const void *vbuf, Size_t count)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Unread) (aTHX_ f, vbuf, count);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1423,7 +1470,7 @@ Perl_PerlIO_write(pTHX_ PerlIO *f, const void *vbuf, Size_t count)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Write) (aTHX_ f, vbuf, count);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1434,7 +1481,7 @@ Perl_PerlIO_seek(pTHX_ PerlIO *f, Off_t offset, int whence)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Seek) (aTHX_ f, offset, whence);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1445,7 +1492,7 @@ Perl_PerlIO_tell(pTHX_ PerlIO *f)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Tell) (aTHX_ f);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1461,13 +1508,13 @@ Perl_PerlIO_flush(pTHX_ PerlIO *f)
 	    }
 	    else {
 		PerlIO_debug("Cannot flush f=%p :%s\n", (void*)f, tab->name);
-		SETERRNO(EBADF, SS$_IVCHAN);
+		SETERRNO(EBADF, SS_IVCHAN);
 		return -1;
 	    }
 	}
 	else {
 	    PerlIO_debug("Cannot flush f=%p\n", (void*)f);
-	    SETERRNO(EBADF, SS$_IVCHAN);
+	    SETERRNO(EBADF, SS_IVCHAN);
 	    return -1;
 	}
     }
@@ -1519,7 +1566,7 @@ Perl_PerlIO_fill(pTHX_ PerlIO *f)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Fill) (aTHX_ f);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1530,7 +1577,7 @@ PerlIO_isutf8(PerlIO *f)
     if (PerlIOValid(f))
 	return (PerlIOBase(f)->flags & PERLIO_F_UTF8) != 0;
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1541,7 +1588,7 @@ Perl_PerlIO_eof(pTHX_ PerlIO *f)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Eof) (aTHX_ f);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1552,7 +1599,7 @@ Perl_PerlIO_error(pTHX_ PerlIO *f)
     if (PerlIOValid(f))
 	return (*PerlIOBase(f)->tab->Error) (aTHX_ f);
     else {
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 	return -1;
     }
 }
@@ -1563,7 +1610,7 @@ Perl_PerlIO_clearerr(pTHX_ PerlIO *f)
     if (PerlIOValid(f))
 	(*PerlIOBase(f)->tab->Clearerr) (aTHX_ f);
     else
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 }
 
 void
@@ -1572,7 +1619,7 @@ Perl_PerlIO_setlinebuf(pTHX_ PerlIO *f)
     if (PerlIOValid(f))
 	(*PerlIOBase(f)->tab->Setlinebuf) (aTHX_ f);
     else
-	SETERRNO(EBADF, SS$_IVCHAN);
+	SETERRNO(EBADF, SS_IVCHAN);
 }
 
 int
@@ -1674,17 +1721,16 @@ Perl_PerlIO_set_ptrcnt(pTHX_ PerlIO *f, STDCHAR * ptr, int cnt)
     }
 }
 
+
 /*--------------------------------------------------------------------------------------*/
 /*
  * utf8 and raw dummy layers
  */
 
 IV
-PerlIOUtf8_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
+PerlIOUtf8_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
 {
-    if (*PerlIONext(f)) {
-	PerlIO_funcs *tab = PerlIOBase(f)->tab;
-	PerlIO_pop(aTHX_ f);
+    if (PerlIOValid(f)) {
 	if (tab->kind & PERLIO_K_UTF8)
 	    PerlIOBase(f)->flags |= PERLIO_F_UTF8;
 	else
@@ -1695,8 +1741,9 @@ PerlIOUtf8_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
 }
 
 PerlIO_funcs PerlIO_utf8 = {
+    sizeof(PerlIO_funcs),
     "utf8",
-    sizeof(PerlIOl),
+    0,
     PERLIO_K_DUMMY | PERLIO_K_UTF8,
     PerlIOUtf8_pushed,
     NULL,
@@ -1723,8 +1770,9 @@ PerlIO_funcs PerlIO_utf8 = {
 };
 
 PerlIO_funcs PerlIO_byte = {
+    sizeof(PerlIO_funcs),
     "bytes",
-    sizeof(PerlIOl),
+    0,
     PERLIO_K_DUMMY,
     PerlIOUtf8_pushed,
     NULL,
@@ -1761,8 +1809,9 @@ PerlIORaw_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers,
 }
 
 PerlIO_funcs PerlIO_raw = {
+    sizeof(PerlIO_funcs),
     "raw",
-    sizeof(PerlIOl),
+    0,
     PERLIO_K_DUMMY,
     PerlIORaw_pushed,
     PerlIOBase_popped,
@@ -1800,44 +1849,46 @@ PerlIOBase_fileno(pTHX_ PerlIO *f)
 }
 
 char *
-PerlIO_modestr(PerlIO *f, char *buf)
+PerlIO_modestr(PerlIO * f, char *buf)
 {
     char *s = buf;
-    IV flags = PerlIOBase(f)->flags;
-    if (flags & PERLIO_F_APPEND) {
-	*s++ = 'a';
-	if (flags & PERLIO_F_CANREAD) {
-	    *s++ = '+';
+    if (PerlIOValid(f)) {
+	IV flags = PerlIOBase(f)->flags;
+	if (flags & PERLIO_F_APPEND) {
+	    *s++ = 'a';
+	    if (flags & PERLIO_F_CANREAD) {
+		*s++ = '+';
+	    }
 	}
-    }
-    else if (flags & PERLIO_F_CANREAD) {
-	*s++ = 'r';
-	if (flags & PERLIO_F_CANWRITE)
-	    *s++ = '+';
-    }
-    else if (flags & PERLIO_F_CANWRITE) {
-	*s++ = 'w';
-	if (flags & PERLIO_F_CANREAD) {
-	    *s++ = '+';
+	else if (flags & PERLIO_F_CANREAD) {
+	    *s++ = 'r';
+	    if (flags & PERLIO_F_CANWRITE)
+		*s++ = '+';
+	}
+	else if (flags & PERLIO_F_CANWRITE) {
+	    *s++ = 'w';
+	    if (flags & PERLIO_F_CANREAD) {
+		*s++ = '+';
+	    }
 	}
-    }
 #ifdef PERLIO_USING_CRLF
-    if (!(flags & PERLIO_F_CRLF))
-	*s++ = 'b';
+	if (!(flags & PERLIO_F_CRLF))
+	    *s++ = 'b';
 #endif
+    }
     *s = '\0';
     return buf;
 }
 
+
 IV
-PerlIOBase_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
+PerlIOBase_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
 {
     PerlIOl *l = PerlIOBase(f);
 #if 0
     const char *omode = mode;
     char temp[8];
 #endif
-    PerlIO_funcs *tab = PerlIOBase(f)->tab;
     l->flags &= ~(PERLIO_F_CANREAD | PERLIO_F_CANWRITE |
 		  PERLIO_F_TRUNCATE | PERLIO_F_APPEND);
     if (tab->Set_ptrcnt != NULL)
@@ -1856,7 +1907,7 @@ PerlIOBase_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
 	    l->flags |= PERLIO_F_TRUNCATE | PERLIO_F_CANWRITE;
 	    break;
 	default:
-	    SETERRNO(EINVAL, LIB$_INVARG);
+	    SETERRNO(EINVAL, LIB_INVARG);
 	    return -1;
 	}
 	while (*mode) {
@@ -1871,7 +1922,7 @@ PerlIOBase_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
 		l->flags |= PERLIO_F_CRLF;
 		break;
 	    default:
-		SETERRNO(EINVAL, LIB$_INVARG);
+		SETERRNO(EINVAL, LIB_INVARG);
 		return -1;
 	    }
 	}
@@ -2182,7 +2233,7 @@ PerlIOUnix_oflags(const char *mode)
      */
     oflags |= O_BINARY;
     if (*mode || oflags == -1) {
-	SETERRNO(EINVAL, LIB$_INVARG);
+	SETERRNO(EINVAL, LIB_INVARG);
 	oflags = -1;
     }
     return oflags;
@@ -2195,9 +2246,9 @@ PerlIOUnix_fileno(pTHX_ PerlIO *f)
 }
 
 IV
-PerlIOUnix_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
+PerlIOUnix_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
 {
-    IV code = PerlIOBase_pushed(aTHX_ f, mode, arg);
+    IV code = PerlIOBase_pushed(aTHX_ f, mode, arg, tab);
     PerlIOUnix *s = PerlIOSelf(f, PerlIOUnix);
     if (*PerlIONext(f)) {
 	/* We never call down so do any pending stuff now */
@@ -2290,8 +2341,10 @@ SSize_t
 PerlIOUnix_read(pTHX_ PerlIO *f, void *vbuf, Size_t count)
 {
     int fd = PerlIOSelf(f, PerlIOUnix)->fd;
-    if (!(PerlIOBase(f)->flags & PERLIO_F_CANREAD))
+    if (!(PerlIOBase(f)->flags & PERLIO_F_CANREAD) ||
+         PerlIOBase(f)->flags & (PERLIO_F_EOF|PERLIO_F_ERROR)) {
 	return 0;
+    }
     while (1) {
 	SSize_t len = PerlLIO_read(fd, vbuf, count);
 	if (len >= 0 || errno != EINTR) {
@@ -2348,7 +2401,7 @@ PerlIOUnix_close(pTHX_ PerlIO *f)
 	}
     }
     else {
-	SETERRNO(EBADF,SS$_IVCHAN);
+	SETERRNO(EBADF,SS_IVCHAN);
 	return -1;
     }
     while (PerlLIO_close(fd) != 0) {
@@ -2365,6 +2418,7 @@ PerlIOUnix_close(pTHX_ PerlIO *f)
 }
 
 PerlIO_funcs PerlIO_unix = {
+    sizeof(PerlIO_funcs),
     "unix",
     sizeof(PerlIOUnix),
     PERLIO_K_RAW,
@@ -2415,7 +2469,12 @@ typedef struct {
 IV
 PerlIOStdio_fileno(pTHX_ PerlIO *f)
 {
-    return PerlSIO_fileno(PerlIOSelf(f, PerlIOStdio)->stdio);
+    FILE *s;
+    if (PerlIOValid(f) && (s = PerlIOSelf(f, PerlIOStdio)->stdio)) {
+	return PerlSIO_fileno(s);
+    }
+    errno = EBADF;
+    return -1;
 }
 
 char *
@@ -2432,27 +2491,32 @@ PerlIOStdio_mode(const char *mode, char *tmode)
     return ret;
 }
 
-/*
- * This isn't used yet ...
- */
 IV
-PerlIOStdio_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
+PerlIOStdio_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
 {
-    if (*PerlIONext(f)) {
-	PerlIOStdio *s = PerlIOSelf(f, PerlIOStdio);
-	char tmode[8];
-	FILE *stdio =
-	    PerlSIO_fdopen(PerlIO_fileno(PerlIONext(f)), mode =
-			   PerlIOStdio_mode(mode, tmode));
-	if (stdio) {
-	    s->stdio = stdio;
-	    /* We never call down so do any pending stuff now */
-	    PerlIO_flush(PerlIONext(f));
-	}
-	else
-	    return -1;
+    PerlIO *n;
+    if (PerlIOValid(f) && PerlIOValid(n = PerlIONext(f))) {
+        PerlIO_funcs *toptab = PerlIOBase(n)->tab;
+        if (toptab == tab) {
+	    /* Top is already stdio - pop self (duplicate) and use original */
+	    PerlIO_pop(aTHX_ f);
+	    return 0;
+	} else {
+	    int fd = PerlIO_fileno(n);
+	    char tmode[8];
+	    FILE *stdio;
+	    if (fd >= 0 && (stdio  = PerlSIO_fdopen(fd,
+			    mode = PerlIOStdio_mode(mode, tmode)))) {
+		PerlIOSelf(f, PerlIOStdio)->stdio = stdio;
+	    	/* We never call down so do any pending stuff now */
+	    	PerlIO_flush(PerlIONext(f));
+	    }
+	    else {
+		return -1;
+	    }
+        }
     }
-    return PerlIOBase_pushed(aTHX_ f, mode, arg);
+    return PerlIOBase_pushed(aTHX_ f, mode, arg, tab);
 }
 
 
@@ -2534,8 +2598,11 @@ PerlIOStdio_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers,
 			s->stdio = stdio;
 			PerlIOUnix_refcnt_inc(fileno(s->stdio));
 		    }
+		    return f;
+		}
+		else {
+		    return NULL;
 		}
-		return f;
 	    }
 	}
 	if (fd >= 0) {
@@ -2613,6 +2680,10 @@ PerlIOStdio_close(pTHX_ PerlIO *f)
     Sock_size_t optlen = sizeof(int);
 #endif
     FILE *stdio = PerlIOSelf(f, PerlIOStdio)->stdio;
+    if (!stdio) {
+	errno = EBADF;
+	return -1;
+    }
     if (PerlIOUnix_refcnt_dec(fileno(stdio)) > 0) {
 	/* Do not close it but do flush any buffers */
 	return PerlIO_flush(f);
@@ -2923,10 +2994,11 @@ PerlIOStdio_fill(pTHX_ PerlIO *f)
 
 
 PerlIO_funcs PerlIO_stdio = {
+    sizeof(PerlIO_funcs),
     "stdio",
     sizeof(PerlIOStdio),
     PERLIO_K_BUFFERED|PERLIO_K_RAW,
-    PerlIOBase_pushed,
+    PerlIOStdio_pushed,
     PerlIOBase_popped,
     PerlIOStdio_open,
     PerlIOBase_binmode,         /* binmode */
@@ -2967,26 +3039,40 @@ PerlIO_funcs PerlIO_stdio = {
 #endif                          /* USE_STDIO_PTR */
 };
 
+/* Note that calls to PerlIO_exportFILE() are reversed using
+ * PerlIO_releaseFILE(), not importFILE. */
 FILE *
-PerlIO_exportFILE(PerlIO *f, const char *mode)
+PerlIO_exportFILE(PerlIO * f, const char *mode)
 {
     dTHX;
-    FILE *stdio;
-    char buf[8];
-    PerlIO_flush(f);
-    if (!mode || !*mode) {
-	mode = PerlIO_modestr(f,buf);
-    }
-    stdio = PerlSIO_fdopen(PerlIO_fileno(f), mode);
-    if (stdio) {
-	if ((f = PerlIO_push(aTHX_ f, &PerlIO_stdio, buf, Nullsv))) {
-	    PerlIOStdio *s = PerlIOSelf(f,PerlIOStdio);
-	    s->stdio = stdio;
+    FILE *stdio = NULL;
+    if (PerlIOValid(f)) {
+	char buf[8];
+	PerlIO_flush(f);
+	if (!mode || !*mode) {
+	    mode = PerlIO_modestr(f, buf);
+	}
+	stdio = PerlSIO_fdopen(PerlIO_fileno(f), mode);
+	if (stdio) {
+	    PerlIOl *l = *f;
+	    /* De-link any lower layers so new :stdio sticks */
+	    *f = NULL;
+	    if ((f = PerlIO_push(aTHX_ f, &PerlIO_stdio, buf, Nullsv))) {
+		PerlIOStdio *s = PerlIOSelf(f, PerlIOStdio);
+		s->stdio = stdio;
+		/* Link previous lower layers under new one */
+		*PerlIONext(f) = l;
+	    }
+	    else {
+		/* restore layers list */
+		*f = l;
+	    }
 	}
     }
     return stdio;
 }
 
+
 FILE *
 PerlIO_findFILE(PerlIO *f)
 {
@@ -3002,6 +3088,7 @@ PerlIO_findFILE(PerlIO *f)
     return PerlIO_exportFILE(f, Nullch);
 }
 
+/* Use this to reverse PerlIO_exportFILE calls. */
 void
 PerlIO_releaseFILE(PerlIO *p, FILE *f)
 {
@@ -3026,7 +3113,7 @@ PerlIO_releaseFILE(PerlIO *p, FILE *f)
  */
 
 IV
-PerlIOBuf_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
+PerlIOBuf_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
 {
     PerlIOBuf *b = PerlIOSelf(f, PerlIOBuf);
     int fd = PerlIO_fileno(f);
@@ -3039,7 +3126,7 @@ PerlIOBuf_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
 	    b->posn = posn;
 	}
     }
-    return PerlIOBase_pushed(aTHX_ f, mode, arg);
+    return PerlIOBase_pushed(aTHX_ f, mode, arg, tab);
 }
 
 PerlIO *
@@ -3052,7 +3139,7 @@ PerlIOBuf_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers,
 	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);
-	if (!next || (*PerlIOBase(f)->tab->Pushed) (aTHX_ f, mode, PerlIOArg) != 0) {
+	if (!next || (*PerlIOBase(f)->tab->Pushed) (aTHX_ f, mode, PerlIOArg, self) != 0) {
 	    return NULL;
 	}
     }
@@ -3474,6 +3561,7 @@ PerlIOBuf_dup(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags)
 
 
 PerlIO_funcs PerlIO_perlio = {
+    sizeof(PerlIO_funcs),
     "perlio",
     sizeof(PerlIOBuf),
     PERLIO_K_BUFFERED|PERLIO_K_RAW,
@@ -3563,9 +3651,9 @@ PerlIOPending_set_ptrcnt(pTHX_ PerlIO *f, STDCHAR * ptr, SSize_t cnt)
 }
 
 IV
-PerlIOPending_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
+PerlIOPending_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
 {
-    IV code = PerlIOBase_pushed(aTHX_ f, mode, arg);
+    IV code = PerlIOBase_pushed(aTHX_ f, mode, arg, tab);
     PerlIOl *l = PerlIOBase(f);
     /*
      * Our PerlIO_fast_gets must match what we are pushed on, or sv_gets()
@@ -3596,6 +3684,7 @@ PerlIOPending_read(pTHX_ PerlIO *f, void *vbuf, Size_t count)
 }
 
 PerlIO_funcs PerlIO_pending = {
+    sizeof(PerlIO_funcs),
     "pending",
     sizeof(PerlIOBuf),
     PERLIO_K_BUFFERED|PERLIO_K_RAW,  /* not sure about RAW here */
@@ -3641,11 +3730,11 @@ typedef struct {
 } PerlIOCrlf;
 
 IV
-PerlIOCrlf_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg)
+PerlIOCrlf_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab)
 {
     IV code;
     PerlIOBase(f)->flags |= PERLIO_F_CRLF;
-    code = PerlIOBuf_pushed(aTHX_ f, mode, arg);
+    code = PerlIOBuf_pushed(aTHX_ f, mode, arg, tab);
 #if 0
     PerlIO_debug("PerlIOCrlf_pushed f=%p %s %s fl=%08" UVxf "\n",
 		 f, PerlIOBase(f)->tab->name, (mode) ? mode : "(Null)",
@@ -3750,13 +3839,16 @@ PerlIOCrlf_get_cnt(pTHX_ PerlIO *f)
 			b->ptr++;       /* say we have read it as far as
 					 * flush() is concerned */
 			b->buf++;       /* Leave space in front of buffer */
+			/* Note as we have moved buf up flush's
+			   posn += ptr-buf
+			   will naturally make posn point at CR
+			 */
 			b->bufsiz--;    /* Buffer is thus smaller */
 			code = PerlIO_fill(f);  /* Fetch some more */
 			b->bufsiz++;    /* Restore size for next time */
 			b->buf--;       /* Point at space */
 			b->ptr = nl = b->buf;   /* Which is what we hand
 						 * off */
-			b->posn--;      /* Buffer starts here */
 			*nl = 0xd;      /* Fill in the CR */
 			if (code == 0)
 			    goto test;  /* fill() call worked */
@@ -3906,6 +3998,7 @@ PerlIOCrlf_binmode(pTHX_ PerlIO *f)
 }
 
 PerlIO_funcs PerlIO_crlf = {
+    sizeof(PerlIO_funcs),
     "crlf",
     sizeof(PerlIOCrlf),
     PERLIO_K_BUFFERED | PERLIO_K_CANCRLF | PERLIO_K_RAW,
@@ -3971,7 +4064,7 @@ PerlIOMmap_map(pTHX_ PerlIO *f)
 		if (!page_size) {
 #if defined(HAS_SYSCONF) && (defined(_SC_PAGESIZE) || defined(_SC_PAGE_SIZE))
 		    {
-			SETERRNO(0, SS$_NORMAL);
+			SETERRNO(0, SS_NORMAL);
 #   ifdef _SC_PAGESIZE
 			page_size = sysconf(_SC_PAGESIZE);
 #   else
@@ -4222,6 +4315,7 @@ PerlIOMmap_dup(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags)
 
 
 PerlIO_funcs PerlIO_mmap = {
+    sizeof(PerlIO_funcs),
     "mmap",
     sizeof(PerlIOMmap),
     PERLIO_K_BUFFERED|PERLIO_K_RAW,
@@ -4489,7 +4583,7 @@ PerlIO_setpos(PerlIO *f, SV *pos)
 	if (f && len == sizeof(Off_t))
 	    return PerlIO_seek(f, *posn, SEEK_SET);
     }
-    SETERRNO(EINVAL, SS$_IVCHAN);
+    SETERRNO(EINVAL, SS_IVCHAN);
     return -1;
 }
 #else
@@ -4509,7 +4603,7 @@ PerlIO_setpos(PerlIO *f, SV *pos)
 #endif
 	}
     }
-    SETERRNO(EINVAL, SS$_IVCHAN);
+    SETERRNO(EINVAL, SS_IVCHAN);
     return -1;
 }
 #endif
@@ -4596,3 +4690,6 @@ PerlIO_sprintf(char *s, int n, const char *fmt, ...)
 
 
 
+
+
+