Fix/table and ldap question empty selection sentinel

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- Filter the '0' empty-selection sentinel in Table and LDAP select questions
 - Fix Table question column type edge cases
 
 ## [1.3.0] - 2026-08-11

src/Model/QuestionType/LdapQuestion.php

@@ -130,6 +130,16 @@ public function getExtraDataConfigClass(): string
         return LdapQuestionConfig::class;
     }
 
+    #[Override]
+    public function prepareEndUserAnswer(Question $question, mixed $answer): mixed
+    {
+        if ($answer === '0' || $answer === 0) {
+            return '';
+        }
+
+        return $answer;
+    }
+
     #[Override]
     public function renderEndUserTemplate(Question|null $question): string
     {

src/Model/QuestionType/TableQuestion.php

@@ -182,6 +182,8 @@ public function prepareEndUserAnswer(Question $question, mixed $answer): mixed
             return [];
         }
 
+        $answer = $this->normalizeDropdownCells($answer, $question);
+
         // Drop empty rows; required columns are enforced by validateAnswer().
         $result = [];
         foreach ($answer as $row) {
@@ -206,6 +208,8 @@ public function validateAnswer(Question $question, mixed $answer): ValidationRes
             return $result;
         }
 
+        $answer = $this->normalizeDropdownCells($answer, $question);
+
         $row_number = 0;
         foreach ($answer as $row) {
             if (!is_array($row)) {
@@ -331,6 +335,46 @@ private function rowHasValue(array $row): bool
         return false;
     }
 
+    /**
+     * @param array<array-key, mixed> $rows
+     * @return array<array-key, mixed>
+     */
+    private function normalizeDropdownCells(array $rows, Question $question): array
+    {
+        $dropdown_indexes = [];
+        foreach ($this->loadConfig($question)->getColumns() as $index => $col) {
+            $fqcn     = $col[TableQuestionConfig::COL_QUESTION_TYPE];
+            $itemtype = $col[TableQuestionConfig::COL_ITEMTYPE] ?? '';
+            if (
+                is_a($fqcn, AbstractQuestionTypeActors::class, true)
+                || (is_a($fqcn, QuestionTypeItem::class, true) && $itemtype !== '' && class_exists($itemtype))
+            ) {
+                $dropdown_indexes[] = $index;
+            }
+        }
+
+        if ($dropdown_indexes === []) {
+            return $rows;
+        }
+
+        foreach ($rows as &$row) {
+            if (!is_array($row)) {
+                continue;
+            }
+
+            foreach ($dropdown_indexes as $index) {
+                $key = 'col_' . $index;
+                if (($row[$key] ?? null) === '0' || ($row[$key] ?? null) === 0) {
+                    $row[$key] = '';
+                }
+            }
+        }
+
+        unset($row);
+
+        return $rows;
+    }
+
     #[Override]
     public function transformConditionValueForComparisons(mixed $value, ?JsonFieldInterface $question_config): string|array
     {

tests/Model/QuestionType/LdapQuestionTest.php

@@ -33,7 +33,9 @@
 
 namespace GlpiPlugin\Advancedforms\Tests\Model\QuestionType;
 
+use Glpi\Form\Question;
 use Glpi\Form\QuestionType\QuestionTypeInterface;
+use Glpi\Tests\FormBuilder;
 use Glpi\Tests\FormTesterTrait;
 use GlpiPlugin\Advancedforms\Model\Config\ConfigurableItemInterface;
 use GlpiPlugin\Advancedforms\Model\QuestionType\LdapQuestion;
@@ -51,6 +53,33 @@ protected function getTestedQuestionType(): QuestionTypeInterface&ConfigurableIt
         return new LdapQuestion();
     }
 
+    /**
+     * Dropdown::show(), which renders this question's field, defaults an
+     * unselected value to "0" instead of an empty string. Without a guard,
+     * that sentinel gets saved and displayed as if it were a real answer.
+     */
+    public function testPrepareEndUserAnswerFiltersEmptySelectionSentinel(): void
+    {
+        $type = new LdapQuestion();
+
+        $this->enableConfigurableItem($type);
+        $builder = new FormBuilder("My form");
+        $builder->addQuestion(
+            "My question",
+            LdapQuestion::class,
+            extra_data: json_encode(['authldap_id' => 1]),
+        );
+
+        $form = $this->createForm($builder);
+        $questions_id = $this->getQuestionId($form, "My question");
+        $question = new Question();
+        $this->assertTrue($question->getFromDB($questions_id));
+
+        $this->assertSame('', $type->prepareEndUserAnswer($question, '0'));
+        $this->assertSame('', $type->prepareEndUserAnswer($question, 0));
+        $this->assertSame('jdoe@example.com', $type->prepareEndUserAnswer($question, 'jdoe@example.com'));
+    }
+
     #[Override]
     protected function validateEditorRenderingWhenEnabled(
         Crawler $html,

tests/Model/QuestionType/TableQuestionValidationTest.php

@@ -35,6 +35,7 @@
 
 use Glpi\Form\AnswersHandler\AnswersHandler;
 use Glpi\Form\Question;
+use Glpi\Form\QuestionType\QuestionTypeAssignee;
 use Glpi\Form\QuestionType\QuestionTypeCheckbox;
 use Glpi\Form\QuestionType\QuestionTypeEmail;
 use Glpi\Form\QuestionType\QuestionTypeNumber;
@@ -767,6 +768,50 @@ public function testCellForAnUnknownColumnIsIgnored(): void
         $this->assertTrue($result->isValid());
     }
 
+    public function testRequiredActorColumnWithEmptySentinelProducesError(): void
+    {
+        $question = $this->makeTableQuestion([
+            $this->column('Assignee', QuestionTypeAssignee::class, required: true),
+            $this->column('Comment', QuestionTypeShortText::class, required: false),
+        ]);
+
+        $result = $this->type->validateAnswer($question, [
+            ['col_0' => '0', 'col_1' => 'a comment'],
+        ]);
+
+        $this->assertFalse($result->isValid());
+        $this->assertCount(1, $result->getErrors());
+    }
+
+    public function testPrepareEndUserAnswerDropsRowWhoseOnlyValueIsActorEmptySentinel(): void
+    {
+        $question = $this->makeTableQuestion([
+            $this->column('Assignee', QuestionTypeAssignee::class, required: false),
+        ]);
+
+        $result = $this->type->prepareEndUserAnswer($question, [
+            ['col_0' => '0'],
+        ]);
+
+        $this->assertSame([], $result);
+    }
+
+    public function testPrepareEndUserAnswerNormalizesActorEmptySentinelToEmptyString(): void
+    {
+        $question = $this->makeTableQuestion([
+            $this->column('Assignee', QuestionTypeAssignee::class, required: false),
+            $this->column('Comment', QuestionTypeShortText::class, required: false),
+        ]);
+
+        $result = $this->type->prepareEndUserAnswer($question, [
+            ['col_0' => '0', 'col_1' => 'a comment'],
+        ]);
+
+        $this->assertSame([
+            ['col_0' => '', 'col_1' => 'a comment'],
+        ], $result);
+    }
+
     /**
      * @param array<array{name: string, question_type: string, required: bool, itemtype: string}> $columns
      */