Non-blocking parser reports incorrect locations when fed with non-zero offset

[dnault]

When feeding a non-blocking parser, the input array offset leaks into the offsets reported by getCurrentLocation() and getTokenLocation().

For example, feeding with an offset of 7 yields tokens whose reported locations are 7 greater than they should be. Likewise the current location reported by the parser is 7 greater than the correct location.

It's not possible for a user to work around this issue by subtracting 7 from the reported locations, because the token location may have been established by an earlier feeding with a different offset.

Jackson version: 2.9.8

Unit test:

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.core.async.ByteArrayFeeder;
import org.junit.Test;

import static java.nio.charset.StandardCharsets.UTF_8;
import static org.junit.Assert.assertEquals;

public class FeedingOffsetTest {

  @Test
  public void inputOffsetShouldNotAffectLocations() throws Exception {
    JsonFactory jsonFactory = new JsonFactory();
    JsonParser parser = jsonFactory.createNonBlockingByteArrayParser();
    ByteArrayFeeder feeder = (ByteArrayFeeder) parser.getNonBlockingInputFeeder();

    byte[] input = "[[[".getBytes(UTF_8);

    feeder.feedInput(input, 2, 3);
    assertEquals(JsonToken.START_ARRAY, parser.nextToken());
    assertEquals(1, parser.getCurrentLocation().getByteOffset()); // ACTUAL = 3
    assertEquals(1, parser.getTokenLocation().getByteOffset());   // ACTUAL = 3

    feeder.feedInput(input, 0, 1);
    assertEquals(JsonToken.START_ARRAY, parser.nextToken());
    assertEquals(2, parser.getCurrentLocation().getByteOffset());
    assertEquals(2, parser.getTokenLocation().getByteOffset());
  }
}

[cowtowncoder]

Thank you for reporting this problem.