Minor fix for read_minibuf_noninteractive on MS-Windows.

 src/minibuf.c (read_minibuf_noninteractive) [WINDOWSNT]: Switch
 stdin to binary mode only if it is connected to a terminal.

Fixes: debbugs:17839

2 files changed, 9 insertions, 2 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 9265051e311..9d5dff49166 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2014-07-12  Eli Zaretskii  <eliz@gnu.org>
+
+        * minibuf.c (read_minibuf_noninteractive) [WINDOWSNT]: Switch
+        stdin to binary mode only if it is connected to a terminal.
+
 2014-07-11  Paul Eggert  <eggert@cs.ucla.edu>
 
         Coalesce extern decls.
diff --git a/src/minibuf.c b/src/minibuf.c
index 1f2fb1fdf3f..e2450b53964 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -241,7 +241,8 @@ read_minibuf_noninteractive (Lisp_Object map, Lisp_Object initial,
     {
       emacs_get_tty (fileno (stdin), &etty);
 #ifdef WINDOWSNT
-      _setmode (fileno (stdin), O_BINARY);
+      if (isatty (fileno (stdin)))
+        _setmode (fileno (stdin), O_BINARY);
 #endif
       suppress_echo_on_tty (fileno (stdin));
     }
@@ -282,7 +283,8 @@ read_minibuf_noninteractive (Lisp_Object map, Lisp_Object initial,
       fprintf (stdout, "\n");
       emacs_set_tty (fileno (stdin), &etty, 0);
 #ifdef WINDOWSNT
-      _setmode (fileno (stdin), O_TEXT);
+      if (isatty (fileno (stdin)))
+        _setmode (fileno (stdin), O_TEXT);
 #endif
     }