The '/' character in JSON property key name isn't encoding in operation path of a JsonPatch as required by RFC6901 - Json Pointer

[dylanbehetre]

Hello,

I had a problem with the JsonPatch implementation of this library.

Actually, if one of the JsonStructure has a property key name that contains a '/', it isn't encode in the operation 'path'. So the property key name is interpreted by JsonPointer as two keys.

But in the RFC6902 - JsonPatch, it's specified :

Additionally, operation objects MUST have exactly one "path" member.
That member's value is a string containing a JSON-Pointer value
[RFC6901] that references a location within the target document (the
"target location") where the operation is performed.

And in the RFC6901 - JsonPointer, it's specified :

3. Syntax

A JSON Pointer is a Unicode string (see [RFC4627], Section 3)
containing a sequence of zero or more reference tokens, each prefixed
by a '/' (%x2F) character.

Because the characters '~' (%x7E) and '/' (%x2F) have special
meanings in JSON Pointer, '~' needs to be encoded as '~0' and '/'
needs to be encoded as '~1' when these characters appear in a
reference token.

Therefore, I understand that the '/' character in a json property key name should be encode in ~1 in the operation path. Therefore, json property key name 'a/b' should have the path 'a~1b'.

The class code below put in light the problem and throw a javax.json.JsonException specified that the JSON Object don't con't contains 'a'. Which is actually true, we have 'a/b' and this is what we are looking for.

import javax.json.Json;
import javax.json.JsonObject;
import javax.json.JsonPatch;
import javax.json.JsonReader;
import javax.json.JsonReaderFactory;
import javax.json.JsonStructure;
import javax.json.JsonValue;
import java.io.StringReader;

class Scratch {
    private static final String FIRST_JSON = "{\n" +
        "  \"a/b\": \"valeurA\"\n" +
        "}\n";

    private static final String SECOND_JSON = "{\n" +
        "  \"a/b\": \"valeurB\"\n" +
        "}\n";

    private static final JsonReaderFactory READER_FACTORY = Json.createReaderFactory(null);

    public static void main(String[] args) {
        try (
            JsonReader firstJsonReader = Scratch.READER_FACTORY.createReader(new StringReader(FIRST_JSON));
            JsonReader secondJsonReader = Scratch.READER_FACTORY.createReader(new StringReader(SECOND_JSON))
        ) {
            JsonStructure firstJsonStructure = firstJsonReader.read();
            JsonStructure secondJsonStructure = secondJsonReader.read();

            JsonPatch jsonPatch = Json.createDiff(firstJsonStructure, secondJsonStructure);
            for (JsonValue jsonValue : jsonPatch.toJsonArray()) {
                JsonObject jsonObject = jsonValue.asJsonObject();
                final String jsonPath = jsonObject.getString("path"); 
                firstJsonStructure.getValue(jsonPath);
            }
        }
    }
}

To fix this problem, I suggest to replace path + '/' + key usage in the method diffObject in the JsonPatchImpl.java, line 224, by a path + '/' + Json.encodePointer(key).

[dylanbehetre]

Pull request created, see jakartaee/jsonp-api#170