emacs-27 06c302d: Fix set-fontset-font with ADD arg non-nil

[Eli Zaretskii]

branch: emacs-27
commit 06c302d425fc2093130479b8aed7da4507d43331
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Fix set-fontset-font with ADD arg non-nil
    
    * src/fontset.c (fontset_add): Fix off-by-one error at TO.
    (Bug#39482)
---
 src/fontset.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/fontset.c b/src/fontset.c
index 22b7618..bca9452 100644
--- 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
     {