Steps to reproduce

Import attached .lss file

Expected result

File imports fine.

Actual result

Throws error

PHP warning

Attempt to read property "sid" on null

/var/www/html/limesurvey700/application/helpers/admin/import_helper.php(3224)

3212 } elseif (strpos($cfieldnameToProcess, 'X') !== false) {
3213 $parts = explode('X', $cfieldnameToProcess);
3214 $qid = null;
3215 $idCandidate = $parts[2];
3216 $search = true;
3217 $knownFieldName = null;
3218 $theQ = null;
3219 while ($search && strlen($idCandidate)) {
3220 foreach ($aQuestionsMapping as $key => $value) {
3221 if (($key === "Q{$idCandidate}") || (strpos($key, "Q{$idCandidate}") !== false)) {
3222 $qid = substr(explode("", $value)[0], 1);
3223 $theQ = Question::model()->findByPk($qid);
3224 $theQuestions = Question::model()->findAll(['condition' => "sid = {$theQ->sid} and gid = {$theQ->gid} and {$theQ->qid} in (qid, parentqid)"]);
3225 $knownFieldName = "{$theQ->sid}X{$theQ->gid}X{$theQ->qid}" . substr($parts[2], strlen($idCandidate));
3226 $search = false;
3227 }
3228 }
3229 if ($search) {
3230 $idCandidate = substr($idCandidate, 0, strlen($idCandidate) - 1);
3231 }
3232 }
3233 if ($qid) {
3234 $insertdata['cfieldname'] = $plusPrefix . getFieldName(Yii::app()->db->tablePrefix . "responses" . $theQ->sid, $knownFieldName, $theQuestions, $theQ->sid, $theQ->gid);
3235 }
3236 }

Stack Trace
#0
–
/var/www/html/limesurvey700/application/helpers/admin/import_helper.php(1400): XMLImportSurvey("/var/www/html/limesurvey700/tmp/jcyxbb4k4fsb6usrx23jy6yrcm2t8h.l...", "<?xml version="1.0" encoding="UTF-8"?> <document> <LimeSurveyDo...", null, null, ...)

1395 } else {
1396 $sExtension = "";
1397 }
1398 switch ($sExtension) {
1399 case 'lss':
1400 $aImportResults = XMLImportSurvey($sFullFilePath, null, $sNewSurveyName, $DestSurveyID, $bTranslateLinksFields, true, $targetSurveyGroup);
1401 if (!empty($aImportResults['newsid'])) {
1402 $SurveyIntegrity = new LimeSurvey\Models\Services\SurveyIntegrity(Survey::model()->findByPk($aImportResults['newsid']));
1403 $SurveyIntegrity->fixSurveyIntegrity();
1404 finalizeSurveyImportFile($aImportResults['newsid'], $baselang);
1405 }