Even if used only by developers to debug readline library do not open
temporary files from public location without O_EXCL (bcn#868822).

---
 lib/readline/util.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- lib/readline/util.c
+++ lib/readline/util.c	2018-09-20 06:47:51.238715688 +0000
@@ -489,10 +489,12 @@ _rl_trace (va_alist)
 
   if (_rl_tracefp == 0)
     _rl_tropen ();
+  if (!_rl_tracefp)
+    goto out;
   vfprintf (_rl_tracefp, format, args);
   fprintf (_rl_tracefp, "\n");
   fflush (_rl_tracefp);
-
+out:
   va_end (args);
 }
 
@@ -512,7 +514,7 @@ _rl_tropen (void)
 #endif
   snprintf (fnbuf, sizeof (fnbuf), "%s/rltrace.%ld", x, (long)getpid());
   unlink(fnbuf);
-  _rl_tracefp = fopen (fnbuf, "w+");
+  _rl_tracefp = fopen (fnbuf, "w+xe");
   return _rl_tracefp != 0;
 }
 
@@ -521,7 +523,8 @@ _rl_trclose (void)
 {
   int r;
 
-  r = fclose (_rl_tracefp);
+  if (_rl_tracefp)
+    r = fclose (_rl_tracefp);
   _rl_tracefp = 0;
   return r;
 }