Fix set-fontset-font with ADD arg non-nil

* src/fontset.c (fontset_add): Fix off-by-one error at TO.
(Bug#39482)

diff --git a/src/fontset.c b/src/fontset.c
index 22b7618d8aa92fdabe177627378099bf9cdc1712..bca9452418eecc494447370353fd2f3ea6dd3dbe 100644 (file)
--- a/src/fontset.c
+++ b/src/fontset.c
@@ -353,7 +353,7 @@ fontset_add (Lisp_Object fontset, Lisp_Object range, Lisp_Object elt, Lisp_Objec
                              (NILP (args[idx]) ? args[1 - idx]
                               : CALLMANY (Fvconcat, args)));
        from = to1 + 1;
-      } while (from < to);
+      } while (from <= to);
     }
   else
     {