[gtk/matthiasc/for-master] gtk-demo: Fix an off-by-one error

[Matthias Clasen <matthiasc src gnome org>]

commit 2faadf1d21a140c0c42872e7915bfeffdd40954c
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Oct 6 18:09:52 2020 -0400

    gtk-demo: Fix an off-by-one error
    
    This was found by the asan build in our ci.

 demos/gtk-demo/unicode-names.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/demos/gtk-demo/unicode-names.c b/demos/gtk-demo/unicode-names.c
index 6c4f21924a..745e1b2db5 100644
--- a/demos/gtk-demo/unicode-names.c
+++ b/demos/gtk-demo/unicode-names.c
@@ -100,7 +100,7 @@ get_break_type_name (GUnicodeBreakType type)
 const char *
 get_combining_class_name (int cclass)
 {
-  const char *classes[255] = { 0, };
+  const char *classes[256] = { 0, };
 
   classes[0] = "Not Reordered";
   classes[1] = "Overlay";