* io.c (rb_io_ungetc): don't fail pushed EOF back.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_6@2086 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/io.c b/io.c
index d2abd6544f..8bd8603c66 100644
--- a/io.c
+++ b/io.c
@@ -989,7 +989,7 @@ rb_io_ungetc(io, c)
     GetOpenFile(io, fptr);
     rb_io_check_readable(fptr);
 
-    if (ungetc(cc, fptr->f) == EOF)
+    if (ungetc(cc, fptr->f) == EOF && cc != EOF)
 	rb_sys_fail(fptr->path);
     return Qnil;
 }