Fix core dump from (format "%#08x" n) patch

Problem reported by Glenn Morris (Bug#29609#13).
* src/editfns.c (styled_format): Null-terminate output,
as later code now expects this.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/editfns.c b/src/editfns.c
index ebf6518994b..084d92346f5 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -4623,6 +4623,7 @@ styled_format (ptrdiff_t nargs, Lisp_Object *args, bool message)
                   /* Don't use sprintf here, as it might mishandle prec.  */
                   sprintf_buf[0] = XINT (arg);
                   sprintf_bytes = prec != 0;
+                  sprintf_buf[sprintf_bytes] = '\0';
                 }
               else if (conversion == 'd' || conversion == 'i')
                 {