Lua: Fix off-by-one preventing accessing last df-other-vectors item by ID, add tests

library/LuaTypes.cpp

@@ -1451,7 +1451,7 @@ void other_vectors_identity::build_metatable(lua_State *state)
 
     auto keys = &index_enum->getKeys()[-index_enum->getFirstItem()];
 
-    for (int64_t i = 0; i < index_enum->getLastItem(); i++)
+    for (int64_t i = 0; i <= index_enum->getLastItem(); i++)
     {
         lua_getfield(state, base+2, keys[i]);
         lua_rawseti(state, base+2, int(i));

test/structures/other_vectors.lua

@@ -0,0 +1,27 @@
+function test.index_name()
+    for _, k in ipairs(df.units_other_id) do
+        expect.eq(df.global.world.units.other[k]._kind, 'container')
+    end
+end
+
+function test.index_name_bad()
+    expect.error_match(function()
+        expect.eq(df.global.world.units.other.SOME_FAKE_NAME, 'container')
+    end, 'not found.$')
+end
+
+function test.index_id()
+    for i in ipairs(df.units_other_id) do
+        expect.eq(df.global.world.units.other[i]._kind, 'container')
+    end
+end
+
+function test.index_id_bad()
+    expect.error_match(function()
+        expect.eq(df.global.world.units.other[df.units_other_id._first_item - 1], 'container')
+    end, 'Cannot read field')
+    expect.error_match(function()
+        expect.eq(df.global.world.units.other[df.units_other_id._last_item + 1], 'container')
+    end, 'Cannot read field')
+end
+