Fix: add guard against null relations

app/Models/Foundation/Summit/Speakers/PresentationSpeaker.php

@@ -532,6 +532,7 @@ public function getPresentationsBySummitAndRole(Summit $summit, $role)
         if ($role == self::ROLE_SPEAKER) {
             $res = $this->presentations->filter(function (PresentationSpeakerAssignment $ps_assignment) use ($summit) {
                 $presentation = $ps_assignment->getPresentation();
+                if(is_null($presentation)) return false;
                 if ($presentation->getSummit()->getId() != $summit->getId()) return false;
                 if ($presentation->getModeratorId() == $this->getId()) return false;
                 if ($presentation->getCreatorId() == $this->getMemberId()) return false;

tests/Unit/Models/PresentationSpeakerPresentationsByRoleTest.php

@@ -0,0 +1,99 @@
+<?php namespace Tests\Unit\Models;
+/**
+ * Copyright 2026 OpenStack Foundation
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+use App\Models\Foundation\Summit\Speakers\PresentationSpeakerAssignment;
+use Mockery;
+use models\summit\Presentation;
+use models\summit\PresentationSpeaker;
+use models\summit\Summit;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Class PresentationSpeakerPresentationsByRoleTest
+ *
+ * Pure unit tests for {@see PresentationSpeaker::getPresentationsBySummitAndRole} with
+ * ROLE_SPEAKER, covering assignments whose presentation is null.
+ *
+ * An assignment's constructor requires a Presentation, so a null one only comes from the
+ * database (a NULL or dangling PresentationID). The orphan here is a real assignment whose
+ * presentation field is nulled, which reproduces that row.
+ *
+ * @package Tests\Unit\Models
+ */
+class PresentationSpeakerPresentationsByRoleTest extends TestCase
+{
+    private const SUMMIT_ID = 1;
+
+    protected function tearDown(): void
+    {
+        Mockery::close();
+        parent::tearDown();
+    }
+
+    private function summit(): Summit
+    {
+        $summit = Mockery::mock(Summit::class);
+        $summit->shouldReceive('getId')->andReturn(self::SUMMIT_ID);
+        return $summit;
+    }
+
+    /**
+     * A presentation the speaker is assigned to as a plain speaker in the given summit.
+     * Moderator and creator ids are non-zero so they can't match a fresh speaker's ids.
+     */
+    private function presentation(Summit $summit): Presentation
+    {
+        $presentation = Mockery::mock(Presentation::class);
+        $presentation->shouldReceive('getSummit')->andReturn($summit);
+        $presentation->shouldReceive('getModeratorId')->andReturn(99);
+        $presentation->shouldReceive('getCreatorId')->andReturn(98);
+        $presentation->shouldReceive('getSpeakerAssignmentsMaxOrder')->andReturn(0);
+        return $presentation;
+    }
+
+    private function addOrphanAssignment(PresentationSpeaker $speaker): void
+    {
+        $assignment = new PresentationSpeakerAssignment(Mockery::mock(Presentation::class), $speaker, 1);
+
+        $presentation_field = new \ReflectionProperty(PresentationSpeakerAssignment::class, 'presentation');
+        $presentation_field->setValue($assignment, null);
+
+        $assignments_field = new \ReflectionProperty(PresentationSpeaker::class, 'presentations');
+        $assignments_field->getValue($speaker)->add($assignment);
+    }
+
+    public function testSkipsAssignmentWithNullPresentationAndKeepsValidOne(): void
+    {
+        $summit = $this->summit();
+        $presentation = $this->presentation($summit);
+
+        $speaker = new PresentationSpeaker();
+        $speaker->addPresentation($presentation);
+        $this->addOrphanAssignment($speaker);
+
+        $result = $speaker->getPresentationsBySummitAndRole($summit, PresentationSpeaker::ROLE_SPEAKER);
+
+        $this->assertSame([$presentation], array_values($result));
+    }
+
+    public function testReturnsEmptyWhenOnlyAssignmentHasNullPresentation(): void
+    {
+        $speaker = new PresentationSpeaker();
+        $this->addOrphanAssignment($speaker);
+
+        $result = $speaker->getPresentationsBySummitAndRole($this->summit(), PresentationSpeaker::ROLE_SPEAKER);
+
+        $this->assertSame([], $result);
+    }
+}