Fix assertions in nth_minibuffer

* src/minibuf.c (nth_minibuffer): Avoid assertion violation when
DEPTHth minibuffer doesn't exist.  (Bug#48337)

diff --git a/src/minibuf.c b/src/minibuf.c
index 167aece973a881c522b7bc0d00d7f70bc7f6e82c..52d1275451b6be73ac60d7e906145c4e69b97606 100644 (file)
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -969,6 +969,8 @@ static Lisp_Object
 nth_minibuffer (EMACS_INT depth)
 {
   Lisp_Object tail = Fnthcdr (make_fixnum (depth), Vminibuffer_list);
+  if (NILP (tail))
+    return Qnil;
   return XCAR (tail);
 }