core.get_objects_inside_radius: Omit removed objects (#6318)

Fixes #6294

doc/lua_api.txt

@@ -2555,7 +2555,7 @@ and `minetest.auth_reload` call the authetification handler.
 * `minetest.add_item(pos, item)`: Spawn item
     * Returns `ObjectRef`, or `nil` if failed
 * `minetest.get_player_by_name(name)`: Get an `ObjectRef` to a player
-* `minetest.get_objects_inside_radius(pos, radius)`
+* `minetest.get_objects_inside_radius(pos, radius)`: returns a list of ObjectRefs
     * `radius`: using an euclidean metric
 * `minetest.set_timeofday(val)`
     * `val` is between `0` and `1`; `0` for midnight, `0.5` for midday

src/script/lua_api/l_env.cpp

@@ -642,9 +642,11 @@ int ModApiEnvMod::l_get_objects_inside_radius(lua_State *L)
 	std::vector<u16>::const_iterator iter = ids.begin();
 	for(u32 i = 0; iter != ids.end(); ++iter) {
 		ServerActiveObject *obj = env->getActiveObject(*iter);
-		// Insert object reference into table
-		script->objectrefGetOrCreate(L, obj);
-		lua_rawseti(L, -2, ++i);
+		if (!obj->m_removed) {
+			// Insert object reference into table
+			script->objectrefGetOrCreate(L, obj);
+			lua_rawseti(L, -2, ++i);
+		}
 	}
 	return 1;
 }