Fix some minor races in hosts lacking mkostemp.

Gnulib's emulation of mkostemp doesn't have races that Emacs's does.
* configure.ac (mkostemp): Remove check for this function;
gnulib does the check now.
(mkstemp): Remove check for this no-longer-used function.
* lib/mkostemp.c, lib/secure_getenv.c, lib/tempname.c, lib/tempname.h:
* m4/mkostemp.m4, m4/secure_getenv.m4, m4/tempname.m4:
New files, copied from Gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* admin/merge-gnulib (GNULIB_MODULES): Add mkostemp.
* lib-src/movemail.c (main):
* lib-src/update-game-score.c (write_scores):
Use mkostemp (which now works on all platforms, due to changes
in the portability layer) rather than mktemp (which has a race)
or mkstemp (which we no longer bother with).
* src/callproc.c (create_temp_file):
* src/filelock.c (create_lock_file):
Assume mkostemp, since it's now provided by Gnulib.

Fixes: debbugs:15015

1 files changed, 19 insertions, 0 deletions

diff --git a/m4/tempname.m4 b/m4/tempname.m4
new file mode 100644
index 00000000000..a6e42dcea81
--- /dev/null
+++ b/m4/tempname.m4
@@ -0,0 +1,19 @@
+#serial 5
+
+# Copyright (C) 2006-2007, 2009-2013 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# glibc provides __gen_tempname as a wrapper for mk[ds]temp.  Expose
+# it as a public API, and provide it on systems that are lacking.
+AC_DEFUN([gl_FUNC_GEN_TEMPNAME],
+[
+  gl_PREREQ_TEMPNAME
+])
+
+# Prerequisites of lib/tempname.c.
+AC_DEFUN([gl_PREREQ_TEMPNAME],
+[
+  :
+])