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, 6 insertions, 6 deletions

diff --git a/lib-src/update-game-score.c b/lib-src/update-game-score.c
index ec8b4317770..1699e305c8d 100644
--- a/lib-src/update-game-score.c
+++ b/lib-src/update-game-score.c
@@ -383,6 +383,7 @@ sort_scores (struct score_entry *scores, int count, int reverse)
 static int
 write_scores (const char *filename, const struct score_entry *scores, int count)
 {
+  int fd;
   FILE *f;
   int i;
   char *tempfile = malloc (strlen (filename) + strlen (".tempXXXXXX") + 1);
@@ -390,12 +391,11 @@ write_scores (const char *filename, const struct score_entry *scores, int count)
     return -1;
   strcpy (tempfile, filename);
   strcat (tempfile, ".tempXXXXXX");
-#ifdef HAVE_MKSTEMP
-  if (mkstemp (tempfile) < 0
-#else
-  if (mktemp (tempfile) != tempfile
-#endif
-      || !(f = fopen (tempfile, "w")))
+  fd = mkostemp (tempfile, 0);
+  if (fd < 0)
+    return -1;
+  f = fdopen (fd, "w");
+  if (! f)
     return -1;
   for (i = 0; i < count; i++)
     if (fprintf (f, "%ld %s %s\n", scores[i].score, scores[i].username,