* io.c (fill_cbuf): finish reading at EOF, and the readconv has

  been cleared by another thread while io_fillbuf() is waiting at
  select().  a patch in [ruby-core:37197] by Hiroshi Shirosaki
  <h.shirosaki AT gmail.com>.  fixed #3840

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32169 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 0 deletions

diff --git a/io.c b/io.c
index fae297990a..4371d5388a 100644
--- a/io.c
+++ b/io.c
@@ -1717,6 +1717,9 @@ fill_cbuf(rb_io_t *fptr, int ec_flags)
             if (fptr->rbuf.len == 0) {
 		READ_CHECK(fptr);
                 if (io_fillbuf(fptr) == -1) {
+		    if (!fptr->readconv) {
+			return MORE_CHAR_FINISHED;
+		    }
                     ds = dp = (unsigned char *)fptr->cbuf.ptr + fptr->cbuf.off + fptr->cbuf.len;
                     de = (unsigned char *)fptr->cbuf.ptr + fptr->cbuf.capa;
                     res = rb_econv_convert(fptr->readconv, NULL, NULL, &dp, de, 0);