Do not change IO.pipe encodings if encodings explicitly given

This commit makes it so that if the binmode option is given with
any encoding arguments, the reader and writer IO objects are
not set to binary encoding.

Fixes [Bug #12989]

1 files changed, 1 insertions, 1 deletions

diff --git a/io.c b/io.c
index 00d3716839..d0257ff42e 100644
--- a/io.c
+++ b/io.c
@@ -10313,7 +10313,7 @@ rb_io_s_pipe(int argc, VALUE *argv, VALUE klass)
 
     extract_binmode(opt, &fmode);
 
-    if (fmode & FMODE_BINMODE) {
+    if ((fmode & FMODE_BINMODE) && v1 == Qnil) {
 	rb_io_ascii8bit_binmode(r);
 	rb_io_ascii8bit_binmode(w);
     }