gettimeofday: port recent C++ fix to Emacs

[gnulib.git] / lib / isatty.c

diff --git a/lib/isatty.c b/lib/isatty.c
index ed8be82..36fbc36 100644 (file)
--- a/lib/isatty.c
+++ b/lib/isatty.c
@@ -1,5 +1,5 @@
 /* isatty() replacement.
-   Copyright (C) 2012 Free Software Foundation, Inc.
+   Copyright (C) 2012-2013 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -21,24 +21,61 @@
 
 /* This replacement is enabled on native Windows.  */
 
+#include <errno.h>
+
 /* Get declarations of the Win32 API functions.  */
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 
+#include "msvc-inval.h"
+
 /* Get _get_osfhandle().  */
 #include "msvc-nothrow.h"
 
-#define IsConsoleHandle(h) (((long) (h) & 3) == 3)
+/* Optimized test whether a HANDLE refers to a console.
+   See <http://lists.gnu.org/archive/html/bug-gnulib/2009-08/msg00065.html>.  */
+#define IsConsoleHandle(h) (((intptr_t) (h) & 3) == 3)
+
+#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+static int
+_isatty_nothrow (int fd)
+{
+  int result;
 
+  TRY_MSVC_INVAL
+    {
+      result = _isatty (fd);
+    }
+  CATCH_MSVC_INVAL
+    {
+      result = 0;
+    }
+  DONE_MSVC_INVAL;
+
+  return result;
+}
+#else
+# define _isatty_nothrow _isatty
+#endif
+
+/* Determine whether FD refers to a console device.  Return 1 if yes.
+   Return 0 and set errno if no. (ptsname_r relies on the errno value.)  */
 int
 isatty (int fd)
 {
-  /* _isatty (fd) tests whether GetFileType of the handle is FILE_TYPE_CHAR.  */
-  if (_isatty (fd))
+  HANDLE h = (HANDLE) _get_osfhandle (fd);
+  if (h == INVALID_HANDLE_VALUE)
+    {
+      errno = EBADF;
+      return 0;
+    }
+  /* _isatty (fd) tests whether GetFileType of the handle is FILE_TYPE_CHAR.
+     But it does not set errno when it returns 0.  */
+  if (_isatty_nothrow (fd))
     {
-      HANDLE h = (HANDLE) _get_osfhandle (fd);
-      return IsConsoleHandle (h);
+      if (IsConsoleHandle (h))
+        return 1;
     }
-  else
-    return 0;
+  errno = ENOTTY;
+  return 0;
 }