perl -e "use open qw{:encoding(UTF-8) :std}; fork;" で落ちる問題のパッチを書こう(まだ駄目です)

01-test.pl

#! perl.exe
use strict;
use warnings;
#use open qw{:std :encoding(UTF-8)}; # これは落ちる
use open qw{:encoding(UTF-8)};       # これは落ちなくなった

my $i = 1;

my $pid = fork;
die "Cannot fork: $!" unless defined $pid;

if ($pid) {
    print "foo $i\n";
} else {
    print "bar\n";
}

02-patch.diff

diff --git a/ext/PerlIO-encoding/encoding.xs b/ext/PerlIO-encoding/encoding.xs
index 03b8850..f9120e4 100644
--- a/ext/PerlIO-encoding/encoding.xs
+++ b/ext/PerlIO-encoding/encoding.xs
@@ -560,6 +560,9 @@ PerlIO *
 PerlIOEncode_dup(pTHX_ PerlIO * f, PerlIO * o,
 		 CLONE_PARAMS * params, int flags)
 {
+    if (!PL_curstackinfo) {
+	return f;
+    }
     if ((f = PerlIOBase_dup(aTHX_ f, o, params, flags))) {
 	PerlIOEncode *fe = PerlIOSelf(f, PerlIOEncode);
 	PerlIOEncode *oe = PerlIOSelf(o, PerlIOEncode);
diff --git a/perlio.c b/perlio.c
index 92fa2be..fa88c5e 100644
--- a/perlio.c
+++ b/perlio.c
@@ -453,7 +453,7 @@ PerlIO_verify_head(pTHX_ PerlIO *f)
  */
 #define PERLIO_TABLE_SIZE 64
 
-static void
+void
 PerlIO_init_table(pTHX)
 {
     if (PL_perlio)
diff --git a/sv.c b/sv.c
index 2bb0346..94e20d5 100644
--- a/sv.c
+++ b/sv.c
@@ -14762,7 +14762,13 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 
 #ifdef PERLIO_LAYERS
     /* Clone PerlIO tables as soon as we can handle general xx_dup() */
-    PerlIO_clone(aTHX_ proto_perl, param);
+    //PerlIO_clone(aTHX_ proto_perl, param);
+    PL_perlio = NULL;
+    PL_known_layers = (PerlIO_list_t*) PerlIO_clone_list(aTHX_ proto_perl->Iknown_layers, param);
+    PL_def_layerlist = (PerlIO_list_t*) PerlIO_clone_list(aTHX_ proto_perl->Idef_layerlist, param);
+    //PerlIO_stdstreams(aTHX);
+    extern PerlIO_init_table(pTHX);
+    PerlIO_init_table(aTHX);
 #endif
 
     PL_envgv		= gv_dup_inc(proto_perl->Ienvgv, param);
@@ -15108,6 +15114,8 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 	SAVEFREESV(PL_compcv);
     }
 
+    //PerlIO_clone(aTHX_ proto_perl, param);
+
     return my_perl;
 }