io.c: discard buffer always

* io.c (copy_stream_fallback_body): discard buffer always before
  exit or exception.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49765 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/io.c b/io.c
index 4610e8514a..015ff6cd5c 100644
--- a/io.c
+++ b/io.c
@@ -10462,11 +10462,11 @@ copy_stream_fallback_body(VALUE arg)
             ssize_t ss;
             rb_str_resize(buf, buflen);
             ss = maygvl_copy_stream_read(1, stp, RSTRING_PTR(buf), l, off);
+            rb_str_resize(buf, ss > 0 ? ss : 0);
             if (ss == -1)
                 return Qnil;
             if (ss == 0)
                 rb_eof_error();
-            rb_str_resize(buf, ss);
             if (off != (off_t)-1)
                 off += ss;
         }