mknod: new module

Solaris 9 mknod("name/",mode,dev) mistakenly creates "name" for
non-directory mode.  FreeBSD 7.2 mknod("dangling/",mode,dev)
mistakenly creates the target of the symlink if run as root.
FreeBSD and OpenBSD mknod("fifo",S_IFIFO|mode,0) fails for non-root.
Use of mknod caused link failures on mingw.

* modules/mknod: New file.
* m4/mknod.m4 (gl_FUNC_MKNOD): Likewise.
* lib/mknod.c (mknod): Likewise.
* m4/sys_stat_h.m4 (gl_SYS_STAT_H_DEFAULTS): Set witness
defaults.
* modules/sys_stat (Makefile.am): Substitute them.
* lib/sys_stat.in.h (mknod): Declare replacement.
* MODULES.html.sh (Support for systems lacking POSIX:2008):
Document it.
* doc/posix-functions/mknod.texi (mknod): Likewise.
* modules/mknod-tests: New test.
* tests/test-mknod.c: Likewise.

Signed-off-by: Eric Blake <ebb9@byu.net>

1 files changed, 14 insertions, 3 deletions

diff --git a/doc/posix-functions/mknod.texi b/doc/posix-functions/mknod.texi
index 2853416cfa..99105eab08 100644
--- a/doc/posix-functions/mknod.texi
+++ b/doc/posix-functions/mknod.texi
@@ -4,15 +4,26 @@
 
 POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/mknod.html}
 
-Gnulib module: ---
+Gnulib module: mknod
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function requires super-user privileges to create a fifo:
+FreeBSD 7.2, OpenBSD 3.8.
+@item
+This function mishandles trailing slash on some platforms:
+FreeBSD 7.2, Solaris 9.
+@item
+This function is missing on some platforms; however, the replacement
+always fails with @code{ENOSYS}:
+mingw.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
 @item
-This function is missing on some platforms:
-mingw.
+Use of this function for anything except fifos is not portable,
+generally requiring super-user privileges and knowledge of supported
+device numbers.
 @end itemize