prevent php8 warnings, fixes #5441

Closes #5441

Merge request studip/studip!4084

8 files changed, 50 insertions, 36 deletions

diff --git a/lib/classes/MvvPerm.php b/lib/classes/MvvPerm.php
index 93f9f44..cc254f5 100644
--- a/lib/classes/MvvPerm.php
+++ b/lib/classes/MvvPerm.php
@@ -39,7 +39,7 @@ class MvvPerm {
     */
     const PERM_ADMIN = 15;
 
-    private static $privileges;
+    private static $privileges = null;
 
     private static $roles;
 
@@ -348,18 +348,18 @@ class MvvPerm {
                 if (count($institutes_assigned_role) === 0
                         || count(array_intersect($institut_ids, $institutes_assigned_role))) {
                     if (!$status) {
-                        $priv = intval(self::$privileges[$mvv_table]['default_table'][$role->rolename]);
+                        $priv = intval(self::$privileges[$mvv_table]['default_table'][$role->rolename] ?? 0);
                     } else {
-                        $priv = intval(self::$privileges[$mvv_table]['table'][$status][$role->rolename]);
+                        $priv = intval(self::$privileges[$mvv_table]['table'][$status][$role->rolename] ?? 0);
                     }
                 } else {
                     $priv = 0;
                 }
             } else {
                 if (!$status) {
-                    $priv = intval(self::$privileges[$mvv_table]['default_table'][$role->rolename]);
+                    $priv = intval(self::$privileges[$mvv_table]['default_table'][$role->rolename] ?? 0);
                 } else {
-                    $priv = intval(self::$privileges[$mvv_table]['table'][$status][$role->rolename]);
+                    $priv = intval(self::$privileges[$mvv_table]['table'][$status][$role->rolename] ?? 0);
                 }
             }
 
@@ -465,33 +465,35 @@ class MvvPerm {
             if (count($institut_ids)) {
                 $institutes_assigned_role = RolePersistence::getAssignedRoleInstitutes($user_id, $role->roleid);
                 // count($institutes_assigned_role) === 0 means global role.
-                if (count($institutes_assigned_role) === 0
-                        || count(array_intersect($institut_ids, $institutes_assigned_role))) {
+                if (
+                    count($institutes_assigned_role) === 0
+                    || count(array_intersect($institut_ids, $institutes_assigned_role))
+                ) {
                     $priv = is_array($field)
-                            ? self::$privileges[$mvv_table]['fields'][$field[0]][$field[1]][$status][$role->rolename]
-                            : self::$privileges[$mvv_table]['fields'][$field][$status][$role->rolename];
+                            ? self::$privileges[$mvv_table]['fields'][$field[0]][$field[1]][$status][$role->rolename] ?? null
+                            : self::$privileges[$mvv_table]['fields'][$field][$status][$role->rolename] ?? null;
                     if (is_null($priv)) {
                         $priv = is_array($field)
-                                ? self::$privileges[$mvv_table]['fields'][$field[0]]['default'][$status][$role->rolename]
-                                : self::$privileges[$mvv_table]['fields'][$field]['default'][$role->rolename];
+                                ? self::$privileges[$mvv_table]['fields'][$field[0]]['default'][$status][$role->rolename] ?? null
+                                : self::$privileges[$mvv_table]['fields'][$field]['default'][$role->rolename] ?? null;
                     }
                     if (is_null($priv)) {
-                        $priv = self::$privileges[$mvv_table]['default_fields'][$role->rolename];
+                        $priv = self::$privileges[$mvv_table]['default_fields'][$role->rolename] ?? null;
                     }
                 } else {
                     $priv = 0;
                 }
             } else {
                 $priv = is_array($field)
-                        ? self::$privileges[$mvv_table]['fields'][$field[0]][$field[1]][$status][$role->rolename]
-                        : self::$privileges[$mvv_table]['fields'][$field][$status][$role->rolename];
+                        ? self::$privileges[$mvv_table]['fields'][$field[0]][$field[1]][$status][$role->rolename] ?? null
+                        : self::$privileges[$mvv_table]['fields'][$field][$status][$role->rolename] ?? null;
                 if (is_null($priv)) {
                     $priv = is_array($field)
-                            ? self::$privileges[$mvv_table]['fields'][$field[0]]['default'][$status][$role->rolename]
-                            : self::$privileges[$mvv_table]['fields'][$field]['default'][$role->rolename];
+                            ? self::$privileges[$mvv_table]['fields'][$field[0]]['default'][$status][$role->rolename] ?? null
+                            : self::$privileges[$mvv_table]['fields'][$field]['default'][$role->rolename] ?? null;
                 }
                 if (is_null($priv)) {
-                    $priv = self::$privileges[$mvv_table]['default_fields'][$role->rolename];
+                    $priv = self::$privileges[$mvv_table]['default_fields'][$role->rolename] ?? null;
                 }
             }
             $priv = intval($priv);
@@ -564,7 +566,7 @@ class MvvPerm {
     {
         if (self::$privileges === null) {
             $cache = StudipCacheFactory::getCache();
-            self::$privileges = unserialize($cache->read(MVV::CACHE_KEY . '/privileges'));
+            self::$privileges = unserialize($cache->read(MVV::CACHE_KEY . '/privileges')) ?: [];
         }
 
         if (self::$privileges[$mvv_table] === null) {
diff --git a/lib/functions.php b/lib/functions.php
index 8d639e8..f08ab88 100644
--- a/lib/functions.php
+++ b/lib/functions.php
@@ -717,7 +717,7 @@ function get_users_online_count($active_time = 10)
         $online_count = $statement->fetchColumn();
         $cache->write("online_count/{$active_time}", $online_count, 180);
     }
-    if ($GLOBALS['user']->id && $GLOBALS['user']->id !== 'nobody') {
+    if (User::findCurrent()) {
         --$online_count;
     }
     return $online_count > 0 ? $online_count : 0;
diff --git a/lib/models/ContentTermsOfUse.class.php b/lib/models/ContentTermsOfUse.class.php
index fb2e592..f87b174 100644
--- a/lib/models/ContentTermsOfUse.class.php
+++ b/lib/models/ContentTermsOfUse.class.php
@@ -205,10 +205,15 @@ class ContentTermsOfUse extends SimpleORMap
                 $seminar = Seminar::GetInstance($context_id);
                 $timed_admission = $seminar->getAdmissionTimeFrame();
 
-                if ($seminar->admission_prelim
+                if (
+                    $seminar->admission_prelim
                     || $seminar->isPasswordProtected()
                     || $seminar->isAdmissionLocked()
-                    || (is_array($timed_admission) && $timed_admission['end_time'] > 0 && $timed_admission['end_time'] < time())
+                    || (
+                        $timed_admission
+                        && $timed_admission['end_time'] > 0
+                        && $timed_admission['end_time'] < time()
+                    )
                 ) {
                     return true;
                 }
diff --git a/lib/models/Courseware/StructuralElement.php b/lib/models/Courseware/StructuralElement.php
index 35a0184..4b29313 100644
--- a/lib/models/Courseware/StructuralElement.php
+++ b/lib/models/Courseware/StructuralElement.php
@@ -267,6 +267,10 @@ class StructuralElement extends \SimpleORMap implements \PrivacyObject, \Feedbac
      */
     public function canEdit($user): bool
     {
+        if (!$user) {
+            return false;
+        }
+
         if ($GLOBALS['perm']->have_perm('root', $user->id)) {
             return true;
         }
@@ -322,13 +326,13 @@ class StructuralElement extends \SimpleORMap implements \PrivacyObject, \Feedbac
     public function canRead($user): bool
     {
         // root darf immer
-        if ($GLOBALS['perm']->have_perm('root', $user->id)) {
+        if ($user && $GLOBALS['perm']->have_perm('root', $user->id)) {
             return true;
         }
 
         switch ($this->range_type) {
             case 'user':
-                if ($this->range_id === $user->id) {
+                if ($user && $this->range_id === $user->id) {
                     return true;
                 }
 
@@ -339,7 +343,7 @@ class StructuralElement extends \SimpleORMap implements \PrivacyObject, \Feedbac
 
                 return $this->hasReadApproval($user);
             case 'course':
-                if (!$GLOBALS['perm']->have_studip_perm('user', $this->range_id, $user->id)) {
+                if (!$user || !$GLOBALS['perm']->have_studip_perm('user', $this->range_id, $user->id)) {
                     return false;
                 }
 
@@ -361,20 +365,20 @@ class StructuralElement extends \SimpleORMap implements \PrivacyObject, \Feedbac
     public function canVisit($user): bool
     {
         // root darf immer
-        if ($GLOBALS['perm']->have_perm('root', $user->id)) {
+        if ($user && $GLOBALS['perm']->have_perm('root', $user->id)) {
             return true;
         }
 
         switch ($this->range_type) {
             case 'user':
-                if ($this->range_id === $user->id) {
+                if ($user && $this->range_id === $user->id) {
                     return true;
                 }
 
                 return $this->hasReadApproval($user);
 
             case 'course':
-                if (!$GLOBALS['perm']->have_studip_perm('user', $this->range_id, $user->id)) {
+                if (!$user || !$GLOBALS['perm']->have_studip_perm('user', $this->range_id, $user->id)) {
                     return false;
                 }
 
@@ -1219,7 +1223,7 @@ SQL;
         if ($this->range_type === 'user') {
             return 'contents/courseware/courseware/' . $unit->id . '#/structural_element/' . $this->id;
         }
- 
+
         return 'course/courseware/courseware/' . $unit->id . '?cid=' . $this->range_id . '#/structural_element/' . $this->id;
     }
 
diff --git a/lib/models/FileRef.php b/lib/models/FileRef.php
index 2a7f485..694c0c5 100644
--- a/lib/models/FileRef.php
+++ b/lib/models/FileRef.php
@@ -224,7 +224,7 @@ class FileRef extends SimpleORMap implements PrivacyObject, FeedbackRange
     public function incrementDownloadCounter()
     {
         if (
-            $this->user_id === User::findCurrent()->id
+            (User::findCurrent() && $this->user_id === User::findCurrent()->id)
             || $this->folder instanceof HomeworkFolder
         ) {
             return 0;
diff --git a/lib/models/SimpleORMap.class.php b/lib/models/SimpleORMap.class.php
index aaf2e7d..19b1381 100644
--- a/lib/models/SimpleORMap.class.php
+++ b/lib/models/SimpleORMap.class.php
@@ -431,8 +431,11 @@ class SimpleORMap implements ArrayAccess, Countable, IteratorAggregate
             self::$schemes = unserialize($cache->read('DB_TABLE_SCHEMES')) ?: [];
         }
         if (!isset(self::$schemes[$db_table])) {
+            $pk = [];
+            $db_fields = [];
+
             $db = DBManager::get()->query("SHOW COLUMNS FROM $db_table");
-            while($rs = $db->fetch(PDO::FETCH_ASSOC)){
+            while ($rs = $db->fetch(PDO::FETCH_ASSOC)){
                 $db_fields[strtolower($rs['Field'])] = [
                     'name' => $rs['Field'],
                     'null' => $rs['Null'],
@@ -440,7 +443,7 @@ class SimpleORMap implements ArrayAccess, Countable, IteratorAggregate
                     'type' => $rs['Type'],
                     'extra' => $rs['Extra']
                 ];
-                if ($rs['Key'] == 'PRI'){
+                if ($rs['Key'] === 'PRI'){
                     $pk[] = strtolower($rs['Field']);
                 }
             }
diff --git a/lib/models/Studiengang.php b/lib/models/Studiengang.php
index ee89abd..432134d 100644
--- a/lib/models/Studiengang.php
+++ b/lib/models/Studiengang.php
@@ -514,12 +514,12 @@ class Studiengang extends ModuleManagementModelTreeItem
         $placeholders = [
             'study_course_name',
             'degree_name',
-            'degree_category'
+            'degree_category',
         ];
         $replacements = [
             $this->name,
-            $this->abschluss->name,
-            $this->abschluss->category->name
+            $this->abschluss->name ?? '?',
+            $this->abschluss->category->name ?? '?',
         ];
         return self::formatDisplayName($template, $placeholders, $replacements);
     }
diff --git a/lib/models/resources/ResourceBooking.class.php b/lib/models/resources/ResourceBooking.class.php
index 84fc9c7..158d4d1 100644
--- a/lib/models/resources/ResourceBooking.class.php
+++ b/lib/models/resources/ResourceBooking.class.php
@@ -1737,8 +1737,8 @@ class ResourceBooking extends SimpleORMap implements PrivacyObject, Studip\Calen
             if ($this->assigned_course_date instanceof CourseDate) {
                 $course = $this->assigned_course_date->course;
                 if ($course instanceof Course) {
-                    $has_perms = $GLOBALS['perm']->have_studip_perm('user', $course->id, $user->id);
-                    $vis_perms = $GLOBALS['perm']->have_perm(Config::get()->SEM_VISIBILITY_PERM, $user->id);
+                    $has_perms = $GLOBALS['perm']->have_studip_perm('user', $course->id, $user->id ?? null);
+                    $vis_perms = $GLOBALS['perm']->have_perm(Config::get()->SEM_VISIBILITY_PERM, $user->id ?? null);
                     if ($has_perms || $vis_perms || $course->visible) {
                         $event_title = $this->getAssignedUserName();
                     }