ltj-jfont: more check

diff --git a/src/ltj-jfont.lua b/src/ltj-jfont.lua
index 1c77e82..84a6ead 100644 (file)
--- a/src/ltj-jfont.lua
+++ b/src/ltj-jfont.lua
@@ -953,9 +953,9 @@ luatexbase.add_to_callback(
       local subtables = {}
       if ft.specification then
         for feat_name,v in pairs(ft.specification.features.normal) do
-           if v==true then
+           if v==true and ft.resources then
               for _,i in pairs(ft.resources.sequences) do
-                 if i.order[1]== feat_name and i.type == 'gpos_single' then
+                 if i.order[1]== feat_name and i.type == 'gpos_single' and type(i.subtables)=='table' then
                     for _,st in pairs(i.subtables) do
                        subtables[st] = true
                     end