Workaround for apparent putc bug in Cygwin.

This fix is required for the stream socket test case to pass.
Some interaction between a stdio stream in line buffering
mode and the putc function causes a stream to lose data.
If we use fputs instead to output a character, the
issue goes away.

* stream.c (se_putc): When compiling for Cygwin, construct
a one-character-long string and use fputs, rather than putc.

1 files changed, 7 insertions, 0 deletions

diff --git a/stream.c b/stream.c
index d4b71dc7..a3d60863 100644
--- a/stream.c
+++ b/stream.c
@@ -454,7 +454,14 @@ static int se_putc(int ch, FILE *f)
 {
   int ret;
   sig_save_enable;
+#ifdef __CYGWIN__
+  {
+    char out[2] = { ch, 0 };
+    ret = fputs(out, f) == EOF ? EOF : ch;
+  }
+#else
   ret = putc(ch, f);
+#endif
   sig_restore_enable;
   return ret;
 }