From 054f5b5284b57503d393c9bdd3e331598f5ddb20 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Tue, 19 Dec 2023 11:15:06 +0900
Subject: [PATCH] mruby-io (io_eof): avoid unnecessary read(2) call

---
 mrbgems/mruby-io/src/io.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mrbgems/mruby-io/src/io.c b/mrbgems/mruby-io/src/io.c
index e70d2ab73..16d58d734 100644
--- a/mrbgems/mruby-io/src/io.c
+++ b/mrbgems/mruby-io/src/io.c
@@ -1648,8 +1648,9 @@ io_eof(mrb_state *mrb, mrb_value io)
 {
   struct mrb_io *fptr = io_get_read_fptr(mrb, io);
 
-  io_buf_fill(mrb, fptr);
+  if (fptr->eof) return mrb_true_value();
   if (fptr->buf->len > 0) return mrb_false_value();
+  io_buf_fill(mrb, fptr);
   return mrb_bool_value(fptr->eof);
 }