From 52781e59e0b15141d06ec0b8524d096606551b93 Mon Sep 17 00:00:00 2001
From: Alex Shinn <ashinn@users.noreply.github.com>
Date: Wed, 12 Oct 2011 22:54:11 +0900
Subject: [PATCH] Using ferror when possible in sexp_maybe_block_port.

---
 sexp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sexp.c b/sexp.c
index 179b4f39..cd6e7dc3 100644
--- a/sexp.c
+++ b/sexp.c
@@ -1986,7 +1986,11 @@ int sexp_maybe_block_port (sexp ctx, sexp in, int forcep) {
     if (sexp_port_flags(in) & O_NONBLOCK) {
       if (!forcep
           && (((c = sexp_read_char(ctx, in)) == EOF)
+#if SEXP_USE_STRING_STREAMS
+              && (ferror(sexp_port_stream(in)) == EAGAIN)
+#else
               && (errno == EAGAIN)
+#endif
               && sexp_opcodep((f=sexp_global(ctx, SEXP_G_THREADS_BLOCKER))))) {
         ((sexp_proc2)sexp_opcode_func(f))(ctx sexp_api_pass(f, 1), in);
         return 1;