Fix Marshal.dump(closed_io) to raise TypeError and allow encoding on closed IO

Mashalling a closed IO object raised "closed stream (IOError)" before instead of TypeError.
This changes IO#(in|ex)ternal_encoding to still return the encoding even if the underlying FD is closed.

Fixes bug #18077

1 files changed, 2 insertions, 4 deletions

diff --git a/io.c b/io.c
index 533542b297..2e4c335aae 100644
--- a/io.c
+++ b/io.c
@@ -12092,9 +12092,8 @@ rb_io_s_copy_stream(int argc, VALUE *argv, VALUE io)
 static VALUE
 rb_io_external_encoding(VALUE io)
 {
-    rb_io_t *fptr;
+    rb_io_t *fptr = RFILE(rb_io_taint_check(io))->fptr;
 
-    GetOpenFile(io, fptr);
     if (fptr->encs.enc2) {
 	return rb_enc_from_encoding(fptr->encs.enc2);
     }
@@ -12117,9 +12116,8 @@ rb_io_external_encoding(VALUE io)
 static VALUE
 rb_io_internal_encoding(VALUE io)
 {
-    rb_io_t *fptr;
+    rb_io_t *fptr = RFILE(rb_io_taint_check(io))->fptr;
 
-    GetOpenFile(io, fptr);
     if (!fptr->encs.enc2) return Qnil;
     return rb_enc_from_encoding(io_read_encoding(fptr));
 }