prevent php8 warnings, fixes #3106

Closes #3106

Merge request studip/studip!2095

10 files changed, 35 insertions, 28 deletions

diff --git a/lib/classes/coursewizardsteps/BasicDataWizardStep.php b/lib/classes/coursewizardsteps/BasicDataWizardStep.php
index ce3b57f..100786b 100644
--- a/lib/classes/coursewizardsteps/BasicDataWizardStep.php
+++ b/lib/classes/coursewizardsteps/BasicDataWizardStep.php
@@ -344,13 +344,13 @@ class BasicDataWizardStep implements CourseWizardStep
         if (!trim($values['name'])) {
             $errors[] = _('Bitte geben Sie den Namen der Veranstaltung an.');
         }
-        if ($values['number'] != '') {
+        if (!empty($values['number'])) {
             $course_number_format = Config::get()->COURSE_NUMBER_FORMAT;
             if ($course_number_format && !preg_match('/^' . $course_number_format . '$/', $values['number'])) {
                 $errors[] = _('Die Veranstaltungsnummer hat ein ungültiges Format.');
             }
         }
-        if (!$values['lecturers']) {
+        if (empty($values['lecturers'])) {
             $errors[] = sprintf(
                 _('Bitte tragen Sie mindestens eine Person als %s ein.'),
                 htmlReady(get_title_for_status('dozent', 1, $values['coursetype']))
@@ -411,7 +411,7 @@ class BasicDataWizardStep implements CourseWizardStep
 
         $course->status = $values['coursetype'];
         $course->name = new I18NString($values['name'], $values['name_i18n'] ?? []);
-        $course->veranstaltungsnummer = $values['number'];
+        $course->veranstaltungsnummer = $values['number'] ?? null;
         $course->beschreibung = new I18NString($values['description'], $values['description_i18n'] ?? []);
         $course->start_semester = Semester::findByTimestamp($values['start_time']);
         $course->institut_id = $values['institute'];
diff --git a/lib/elearning/ELearningUtils.class.php b/lib/elearning/ELearningUtils.class.php
index 30c40c4..d027e37 100644
--- a/lib/elearning/ELearningUtils.class.php
+++ b/lib/elearning/ELearningUtils.class.php
@@ -472,6 +472,7 @@ class ELearningUtils
                           FROM object_contentmodules
                           WHERE module_type = 'crs' AND object_id = " . $db->quote($sem_id))
                         ->fetchAll(PDO::FETCH_ASSOC);
+        $courses = [];
         foreach ($rs as $row) {
             $courses[$row['system_type']] = $row['module_id'];
         }
@@ -479,23 +480,26 @@ class ELearningUtils
         $connected_courses = [
             'courses' => [],
         ];
-        if (is_array($courses))
-            foreach ($courses as $system_type => $crs_id)
+        if (is_array($courses)) {
+            foreach ($courses as $system_type => $crs_id) {
                 if (self::isCMSActive($system_type)) {
                     self::loadClass($system_type);
                     $connected_courses['courses'][$system_type] = [
-                        'url' => URLHelper::getLink($connected_cms[$system_type]->link->cms_link . '?client_id=' . $connected_cms[$system_type]->getClientId() . '&cms_select=' . $system_type . '&ref_id=' . $crs_id . '&type=crs&target=start'),
-                        'cms_name' => $connected_cms[$system_type]->getName()];
+                        'url'      => URLHelper::getLink($connected_cms[$system_type]->link->cms_link . '?client_id=' . $connected_cms[$system_type]->getClientId() . '&cms_select=' . $system_type . '&ref_id=' . $crs_id . '&type=crs&target=start'),
+                        'cms_name' => $connected_cms[$system_type]->getName()
+                    ];
                     // gegebenenfalls zugeordnete Module aktualisieren
                     if (Request::option('update')) {
                         if ((method_exists($connected_cms[$system_type], "updateConnections"))) {
-                            $connected_cms[$system_type]->updateConnections( $crs_id );
+                            $connected_cms[$system_type]->updateConnections($crs_id);
                         }
                     }
                     if (method_exists($connected_cms[$system_type]->permissions, 'CheckUserPermissions')) {
                         $connected_cms[$system_type]->permissions->CheckUserPermissions($crs_id);
                     }
                 }
+            }
+        }
 
         if ($connected_courses['courses']) {
             if (count($connected_courses['courses']) > 1) {
diff --git a/lib/filesystem/PublicFolder.php b/lib/filesystem/PublicFolder.php
index 15fdf34..6b06ac9 100644
--- a/lib/filesystem/PublicFolder.php
+++ b/lib/filesystem/PublicFolder.php
@@ -60,7 +60,7 @@ class PublicFolder extends StandardFolder
     public function __get($attribute)
     {
         if ($attribute === 'viewable') {
-            return $this->folderdata['data_content']['viewable'];
+            return !empty($this->folderdata['data_content']['viewable']);
         }
         return $this->folderdata[$attribute];
     }
diff --git a/lib/models/Course.class.php b/lib/models/Course.class.php
index e16df06..4c471ea 100644
--- a/lib/models/Course.class.php
+++ b/lib/models/Course.class.php
@@ -341,7 +341,7 @@ class Course extends SimpleORMap implements Range, PrivacyObject, StudipItem, Fe
     {
         $end_semester = $this->semesters->last();
         $start_semester = $this->semesters->first();
-        if ($start_semester->id === $semester->id) {
+        if ($start_semester && $start_semester->id === $semester->id) {
             return;
         }
         if ($end_semester) {
@@ -369,7 +369,9 @@ class Course extends SimpleORMap implements Range, PrivacyObject, StudipItem, Fe
     {
         $end_semester = $this->semesters->last();
         $start_semester = $this->semesters->first();
-        if ((is_null($end_semester) && is_null($semester)) || ($end_semester->id === $semester->id)) {
+        if (
+            (is_null($end_semester) && is_null($semester))
+            || ($end_semester && $semester && $end_semester->id === $semester->id)) {
             return;
         }
         if ($start_semester) {
diff --git a/lib/models/OERMaterial.php b/lib/models/OERMaterial.php
index ea36035..f0e101d 100644
--- a/lib/models/OERMaterial.php
+++ b/lib/models/OERMaterial.php
@@ -390,8 +390,10 @@ class OERMaterial extends SimpleORMap
         }
         $url = $this->getDownloadUrl();
         $headers = get_headers($url, true, get_default_http_stream_context($url));
-        if ($headers['Content-Disposition']
-            && substr($headers['Content-Disposition'], 0, strlen('attachment')) === 'attachment') {
+        if (
+            !empty($headers['Content-Disposition'])
+            && substr($headers['Content-Disposition'], 0, strlen('attachment')) === 'attachment'
+        ) {
             //in this case the server forces to download the document and we cannot display it in an iframe:
             return false;
         }
diff --git a/lib/models/SimpleCollection.class.php b/lib/models/SimpleCollection.class.php
index 11dd296..4228599 100644
--- a/lib/models/SimpleCollection.class.php
+++ b/lib/models/SimpleCollection.class.php
@@ -592,7 +592,7 @@ class SimpleCollection extends StudipArrayObject
     public function val($key)
     {
         $first = $this->first();
-        return $first[$key] ?: null;
+        return $first[$key] ?? null;
     }
 
     /**
diff --git a/lib/plugins/core/CorePlugin.php b/lib/plugins/core/CorePlugin.php
index 0bba289..7f1aaed 100644
--- a/lib/plugins/core/CorePlugin.php
+++ b/lib/plugins/core/CorePlugin.php
@@ -64,10 +64,10 @@ abstract class CorePlugin
     {
         $metadata = $this->getMetadata();
         $language = getUserLanguage(User::findCurrent()->id);
-        if ($metadata['descriptionlong_' . $language]) {
+        if (!empty($metadata['descriptionlong_' . $language])) {
             return $metadata['descriptionlong_' . $language];
         }
-        if ($metadata['description_' . $language]) {
+        if (!empty($metadata['description_' . $language])) {
             return $metadata['description_' . $language];
         }
         $description = $metadata['descriptionlong'] ?? $metadata['description'];
diff --git a/lib/plugins/core/StudIPPlugin.class.php b/lib/plugins/core/StudIPPlugin.class.php
index a3dacb6..be2c776 100644
--- a/lib/plugins/core/StudIPPlugin.class.php
+++ b/lib/plugins/core/StudIPPlugin.class.php
@@ -89,10 +89,10 @@ abstract class StudIPPlugin
     {
         $metadata = $this->getMetadata();
         $language = getUserLanguage(User::findCurrent()->id);
-        if ($metadata['descriptionlong_' . $language]) {
+        if (!empty($metadata['descriptionlong_' . $language])) {
             return $metadata['descriptionlong_' . $language];
         }
-        if ($metadata['description_' . $language]) {
+        if (!empty($metadata['description_' . $language])) {
             return $metadata['description_' . $language];
         }
         $description = $metadata['descriptionlong'] ?? $metadata['description'];
diff --git a/lib/plugins/engine/PluginManager.class.php b/lib/plugins/engine/PluginManager.class.php
index 7fb69bc..39f4e87 100644
--- a/lib/plugins/engine/PluginManager.class.php
+++ b/lib/plugins/engine/PluginManager.class.php
@@ -87,9 +87,9 @@ class PluginManager
                 'automatic_update_url'    => $plugin['automatic_update_url'],
                 'automatic_update_secret' => $plugin['automatic_update_secret'],
                 'description'             => $plugin['description'],
-                'description_mode'         => $plugin['description_mode'],
-                'highlight_until'         => $plugin['highlight_until'],
-                'highlight_text'          => $plugin['highlight_text']
+                'description_mode'        => $plugin['description_mode'] ?? null,
+                'highlight_until'         => $plugin['highlight_until'] ?? null,
+                'highlight_text'          => $plugin['highlight_text'] ?? null,
             ];
         }
     }
diff --git a/lib/visual.inc.php b/lib/visual.inc.php
index 8503a5c..2b37a64 100644
--- a/lib/visual.inc.php
+++ b/lib/visual.inc.php
@@ -399,14 +399,13 @@ function symbol ($text = '')
 function mila ($titel, $size = 60) {
     global $auth;
 
-    if ($auth->auth["jscript"] AND $size == 60) {
+    if (!empty($auth->auth['jscript']) && $size == 60) {
         //hier wird die maximale Laenge berechnet, nach der Abgeschnitten wird (JS dynamisch)
-        if (mb_strlen ($titel) >$auth->auth["xres"] / 13)
-            $titel=mb_substr($titel, 0, $auth->auth["xres"] / 13)."... ";
-    }
-    else {
-        if (mb_strlen ($titel) >$size)
-            $titel=mb_substr($titel, 0, $size)."... ";
+        if (mb_strlen($titel) > $auth->auth['xres'] / 13) {
+            $titel = mb_substr($titel, 0, $auth->auth['xres'] / 13) . '... ';
+        }
+    } elseif (mb_strlen ($titel) >$size) {
+        $titel = mb_substr($titel, 0, $size) . '... ';
     }
     return $titel;
 }