fix-311: add a comment and a detailed test-case

Author: pboettch

src/json-validator.cpp

@@ -226,6 +226,7 @@ class root_schema
 			// for each token create an object, if not already existing
 			auto unk_kw = &file.unknown_keywords;
 			for (auto &rt : ref_tokens) {
+				// create a json_pointer from rt as rt can be an stringified integer doing find on an array won't work
 				json::json_pointer rt_ptr{"/" + rt};
 				if (unk_kw->contains(rt_ptr) == false)
 					(*unk_kw)[rt] = json::object();

test/issue-311/instance.json

@@ -1,3 +1,4 @@
 {
-  "element": [1]
+  "element": [1],
+  "element2": "test"
 }

test/issue-311/schema.json

@@ -3,14 +3,21 @@
   "properties": {
     "element": {
       "$ref": "#/$defs/element"
+    },
+    "element2": {
+      "$ref": "#/$defs/element/items/0/$defs/element2"
     }
   },
   "$defs": {
     "element": {
       "type": "array",
       "items": [
         {
-          "$comment": "the comment should not lead to fail of loading schema",
+          "$defs": {
+            "element2": {
+              "type": "string"
+            }
+          },
           "type": "number"
         }
       ]