The first solved is not calculated for some case

[tossy310]

Description of the problem

DOMjudge is unable to calculate first solved data correctly in a specific case described below.

Recalculation (Refresh scoreboard cache from jury UI) can recalculates correctly, but it'd be great if DOMjudge can handle this case.

Your environment

Any of DOMjudge 8.2.1, 8.2.2, 2cd74e9 (using docker-contributor image on Ubuntu 22.04)

Steps to reproduce

If the following happens in this order for a specific problem, the first solved is not calculated:

1. Team A submits a solution.
2. Team B submits a solution.
3. Team B's solution is returned as accepted. At this point, Team A's solution is still under judging.
4. Team A's solution is returned as incorrect.

At the point of returning the result of Team B (step 3), the first solved cannot be determined.
However, once the Team A's submission is returned (at step 4), because there's no pending submission that was submitted before the Team B's submission, the Team B's submission is expected to be marked as the first solved.

For local testing, it's easy to reproduce this by extending timelimit of a problem longer (e.g. 60 seconds) and submitting a TLE solution as a team A's one.

Expected behaviour

Once the Team B's solution can be determined as the first solved, then the scoreboard shows it.

Actual behaviour

The first solved is still N/A even after the first solved can be determined.

Requesting recalculation of the scoreboard fixes it.

[eldering]

This sounds very similar to #2105. Is this already fixed in main @nickygerritsen ?

[nickygerritsen]

Seems not since @tossy310 tested it there as well. We should investigate

[tossy310]

Yes, I've tested on the HEAD of main, and the issue exists there as well.

If I read code correctly, the problem is that this part of code

domjudge/webapp/src/Service/ScoreboardService.php

Lines 417 to 467 in 2cd74e9

	// See if this submission was the first to solve this problem.
	// Only relevant if it was correct in the first place.
	$firstToSolve = false;
	if ($correctJury) {
	$params = [
	'cid' => $contest->getCid(),
	'probid' => $problem->getProbid(),
	'teamSortOrder' => $team->getCategory()->getSortorder(),
	/** @phpstan-ignore-next-line $absSubmitTime is always set when $correctJury is true */
	'submitTime' => $absSubmitTime,
	'correctResult' => Judging::RESULT_CORRECT,
	];
	// Find out how many valid submissions were submitted earlier
	// that have a valid judging that is correct, or are awaiting judgement.
	// Only if there are 0 found, we are definitely the first to solve this problem.
	// To find relevant submissions/judgings:
	// - submission needs to be valid (not invalidated)
	// - a valid judging is present, but
	// - either it's still ongoing (pending judgement, could be correct)
	// - or already judged to be correct (if it is judged but not correct,
	// it is not a first to solve)
	// - or the submission is still queued for judgement (judgehost is NULL).
	$verificationRequiredExtra = $verificationRequired ? 'OR j.verified = 0' : '';
	if ($useExternalJudgements) {
	$firstToSolve = 0 == $this->em->getConnection()->fetchOne('
	SELECT count(*) FROM submission s
	LEFT JOIN external_judgement ej USING (submitid)
	LEFT JOIN external_judgement ej2 ON ej2.submitid = s.submitid AND ej2.starttime > ej.starttime
	LEFT JOIN team t USING(teamid)
	LEFT JOIN team_category tc USING (categoryid)
	WHERE s.valid = 1 AND
	(ej.result IS NULL OR ej.result = :correctResult '.
	$verificationRequiredExtra.') AND
	s.cid = :cid AND s.probid = :probid AND
	tc.sortorder = :teamSortOrder AND
	round(s.submittime,4) < :submitTime', $params);
	} else {
	$firstToSolve = 0 == $this->em->getConnection()->fetchOne('
	SELECT count(*) FROM submission s
	LEFT JOIN judging j ON (s.submitid=j.submitid AND j.valid=1)
	LEFT JOIN team t USING (teamid)
	LEFT JOIN team_category tc USING (categoryid)
	WHERE s.valid = 1 AND
	(j.judgingid IS NULL OR j.result IS NULL OR j.result = :correctResult '.
	$verificationRequiredExtra.') AND
	s.cid = :cid AND s.probid = :probid AND
	tc.sortorder = :teamSortOrder AND
	round(s.submittime,4) < :submitTime', $params);
	}
	}

is responsible to update first-to-solve, but this is called only for the corresponding team's submission. (except recalculation of the cache).

#527 (an old PR) changed logics around here, and it prevents updating first-to-solve at step 3 in my reproduction step, but it didn't add any logic to recalculate first-to-solve at step 4 in the step.

[nickygerritsen]

I opened a PR with a potential fix. Thanks for finding this!