From 55f438d8d9a30dab45a2be30960e6d475a2baa14 Mon Sep 17 00:00:00 2001
From: orshih6 <34618353+orshih6@users.noreply.github.com>
Date: Sun, 25 Oct 2026 00:46:12 +0000
Subject: [PATCH] fix: skip short answer validation for empty optional answers

---
 lib/Service/SubmissionService.php            |  6 +++--
 tests/Unit/Service/SubmissionServiceTest.php | 24 ++++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/lib/Service/SubmissionService.php b/lib/Service/SubmissionService.php
index 278fb2828..95024563a 100644
--- a/lib/Service/SubmissionService.php
+++ b/lib/Service/SubmissionService.php
@@ -699,8 +699,10 @@ public function validateSubmission(array $questions, array $answers, string $for
 				}
 			}
 
-			// Handle custom validation of short answers
-			if ($question['type'] === Constants::ANSWER_TYPE_SHORT && !$this->validateShortQuestion($question, $answers[$questionId][0])) {
+			// Handle custom validation of short answers, empty answers are not stored so skip validation for them
+			if ($question['type'] === Constants::ANSWER_TYPE_SHORT
+				&& $answers[$questionId][0] !== ''
+				&& !$this->validateShortQuestion($question, $answers[$questionId][0])) {
 				throw new \InvalidArgumentException(sprintf('Invalid input for question "%s".', $question['text']));
 			}
 
diff --git a/tests/Unit/Service/SubmissionServiceTest.php b/tests/Unit/Service/SubmissionServiceTest.php
index e3d19a7e4..551b1c6d3 100644
--- a/tests/Unit/Service/SubmissionServiceTest.php
+++ b/tests/Unit/Service/SubmissionServiceTest.php
@@ -969,6 +969,30 @@ public static function dataValidateSubmission() {
 				// Expected Result
 				'Invalid input for question "q1".',
 			],
+			'empty-short-email-not-required' => [
+				// Questions
+				[
+					['id' => 1, 'type' => 'short', 'text' => 'q1', 'isRequired' => false, 'extraSettings' => ['validationType' => 'email']]
+				],
+				// Answers
+				[
+					'1' => ['']
+				],
+				// Expected Result
+				null,
+			],
+			'empty-short-email-required' => [
+				// Questions
+				[
+					['id' => 1, 'type' => 'short', 'text' => 'q1', 'isRequired' => true, 'extraSettings' => ['validationType' => 'email']]
+				],
+				// Answers
+				[
+					'1' => ['']
+				],
+				// Expected Result
+				'Question "q1" is required.',
+			],
 			'invalid-short-regex-not-matching' => [
 				// Questions
 				[