Remove redundant AC_SUBST invocation.

[gnulib.git] / doc / posix-functions / stdout.texi

diff --git a/doc/posix-functions/stdout.texi b/doc/posix-functions/stdout.texi
index bdeb977..23a0e96 100644 (file)
--- a/doc/posix-functions/stdout.texi
+++ b/doc/posix-functions/stdout.texi
@@ -17,4 +17,11 @@ stdout is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x.
 One workaround is to use freopen(NULL, ``w'', stdout) on Cygwin 1.5.21
 or newer.  Another is to use the gnulib ftello module and do
 ftello(stdout).
+@item
+POSIX states that a setuid application can guarantee that fd 1 is
+open, but some systems guarantee this even for non-setuid programs.
+If an application is executed with fd 1 closed, use of @code{stdout}
+can affect an unrelated file that happened to be assigned to fd 1.
+The gnulib *-safer modules may be used to guarantee that fd 1 stays
+reserved for @code{stdout}.
 @end itemize