fix php8 warnings, fixes #1679

Closes #1679

Merge request studip/studip!1084

11 files changed, 40 insertions, 33 deletions

diff --git a/lib/classes/ForumHelpers.php b/lib/classes/ForumHelpers.php
index ed478ad..3054dbc 100644
--- a/lib/classes/ForumHelpers.php
+++ b/lib/classes/ForumHelpers.php
@@ -194,7 +194,7 @@ class ForumHelpers {
             }
         }
 
-        return $online_status[$user_id] ?: 'offline';
+        return $online_status[$user_id] ?? 'offline';
     }
 
     /**
diff --git a/lib/classes/I18NString.php b/lib/classes/I18NString.php
index aebe1c8..b8d666b 100644
--- a/lib/classes/I18NString.php
+++ b/lib/classes/I18NString.php
@@ -332,7 +332,7 @@ class I18NString implements JsonSerializable
         $data = [];
         foreach (array_keys(Config::get()->CONTENT_LANGUAGES) as $lang) {
             if ($lang != self::getDefaultLanguage()) {
-                $data[$lang] = mb_strlen($values[$lang]) ? $values[$lang] : null;
+                $data[$lang] = $values[$lang] ?? null;
             }
         }
         return $data;
diff --git a/lib/classes/LinkButton.class.php b/lib/classes/LinkButton.class.php
index 6d60da8..f203841 100644
--- a/lib/classes/LinkButton.class.php
+++ b/lib/classes/LinkButton.class.php
@@ -36,17 +36,16 @@ class LinkButton extends Interactable
     public function __toString()
     {
         // add "button" to attribute @class
-        $this->attributes['class'] .= ' button';
-
-        $attributes = [];
-        ksort($this->attributes);
-        foreach ($this->attributes as $k => $v) {
-            $attributes[] = sprintf(' %s="%s"', $k, htmlReady($v));
+        if (!isset($this->attributes['class'])) {
+            $this->attributes['class'] = '';
         }
+        $this->attributes['class'] .= ' button';
 
         // TODO: URLHelper...?!
-        return sprintf('<a%s>%s</a>',
-                       join('', $attributes),
-                       htmlReady($this->label));
+        return sprintf(
+            '<a %s>%s</a>',
+            arrayToHtmlAttributes($this->attributes),
+            htmlReady($this->label)
+        );
     }
 }
diff --git a/lib/classes/ModulesNotification.class.php b/lib/classes/ModulesNotification.class.php
index ae86645..888052a 100644
--- a/lib/classes/ModulesNotification.class.php
+++ b/lib/classes/ModulesNotification.class.php
@@ -41,13 +41,18 @@ class ModulesNotification
     public $registered_notification_modules = [];
     public $subject;
 
-    function __construct ()
+    public function __construct ()
     {
         foreach (MyRealmModel::getDefaultModules() as $id => $module) {
-            if (!is_object($module)) continue;
+            if (!is_object($module)) {
+                continue;
+            }
+
+            $metadata = $module->getMetadata();
+
             $this->registered_notification_modules[$id] = [
-                'icon' => $module->getMetadata()['icon'],
-                'name' => $module->getMetadata()['displayname'] ?: $module->getPluginName()
+                'icon' => $metadata['icon'],
+                'name' => !empty($metadata['displayname'])  ? $metadata['displayname'] : $module->getPluginName(),
             ];
             if ($module instanceof CoreOverview) {
                 $this->registered_notification_modules[$id]['name'] = _("Ankündigungen");
diff --git a/lib/classes/MultiPersonSearch.class.php b/lib/classes/MultiPersonSearch.class.php
index 1b37cb0..eafcdbb 100644
--- a/lib/classes/MultiPersonSearch.class.php
+++ b/lib/classes/MultiPersonSearch.class.php
@@ -83,7 +83,7 @@ class MultiPersonSearch {
      * @return array containing all new persons
      */
     public function getAddedUsers() {
-        return $_SESSION['multipersonsearch'][$this->name]['added'] ? : [];
+        return $_SESSION['multipersonsearch'][$this->name]['added'] ?? [];
     }
 
     /**
@@ -490,17 +490,19 @@ class MultiPersonSearch {
      * restores the internal data from a session.
      */
     public function restoreFromSession() {
-        $this->title = $_SESSION['multipersonsearch'][$this->name]['title'];
-        $this->description = $_SESSION['multipersonsearch'][$this->name]['description'];
-        $this->quickfilterIds = $_SESSION['multipersonsearch'][$this->name]['quickfilterIds'];
-        $this->additionalHMTL = $_SESSION['multipersonsearch'][$this->name]['additionalHMTL'];
-        $this->executeURL = html_entity_decode($_SESSION['multipersonsearch'][$this->name]['executeURL']);
-        $this->jsFunction = $_SESSION['multipersonsearch'][$this->name]['jsFunction'];
-        $this->defaultSelectableUsersIDs = $_SESSION['multipersonsearch'][$this->name]['defaultSelectableUsersIDs'];
-        $this->defaultSelectedUsersIDs = $_SESSION['multipersonsearch'][$this->name]['defaultSelectedUsersIDs'];
-        $this->searchObject = unserialize($_SESSION['multipersonsearch'][$this->name]['searchObject']);
-        $this->navigationItem = $_SESSION['multipersonsearch'][$this->name]['navigationItem'];
-        $this->dataDialogStatus = $_SESSION['multipersonsearch'][$this->name]['dataDialogStatus'];
+        if (isset($_SESSION['multipersonsearch'][$this->name])) {
+            $this->title = $_SESSION['multipersonsearch'][$this->name]['title'];
+            $this->description = $_SESSION['multipersonsearch'][$this->name]['description'];
+            $this->quickfilterIds = $_SESSION['multipersonsearch'][$this->name]['quickfilterIds'];
+            $this->additionalHMTL = $_SESSION['multipersonsearch'][$this->name]['additionalHMTL'];
+            $this->executeURL = html_entity_decode($_SESSION['multipersonsearch'][$this->name]['executeURL']);
+            $this->jsFunction = $_SESSION['multipersonsearch'][$this->name]['jsFunction'];
+            $this->defaultSelectableUsersIDs = $_SESSION['multipersonsearch'][$this->name]['defaultSelectableUsersIDs'];
+            $this->defaultSelectedUsersIDs = $_SESSION['multipersonsearch'][$this->name]['defaultSelectedUsersIDs'];
+            $this->searchObject = unserialize($_SESSION['multipersonsearch'][$this->name]['searchObject']);
+            $this->navigationItem = $_SESSION['multipersonsearch'][$this->name]['navigationItem'];
+            $this->dataDialogStatus = $_SESSION['multipersonsearch'][$this->name]['dataDialogStatus'];
+        }
     }
 
     /**
diff --git a/lib/classes/SemBrowse.class.php b/lib/classes/SemBrowse.class.php
index 12de227..f9eed7f 100644
--- a/lib/classes/SemBrowse.class.php
+++ b/lib/classes/SemBrowse.class.php
@@ -1298,7 +1298,7 @@ class SemBrowse {
         }
 
         // set default values
-        if (!$_SESSION['sem_browse_data']['default_sem']) {
+        if (empty($_SESSION['sem_browse_data']['default_sem'])) {
             $_SESSION['sem_browse_data']['default_sem'] =
                 Semester::getIndexById(self::getDefaultSemester(), true, true)
                         ?: 'all';
diff --git a/lib/classes/SemClass.class.php b/lib/classes/SemClass.class.php
index dbbbcd7..b6ccb82 100644
--- a/lib/classes/SemClass.class.php
+++ b/lib/classes/SemClass.class.php
@@ -328,7 +328,8 @@ class SemClass implements ArrayAccess
      */
     public function isModuleMandatory($module)
     {
-        return $this->data['modules'][$module]['sticky']
+        return isset($this->data['modules'][$module])
+            && $this->data['modules'][$module]['sticky']
             && $this->data['modules'][$module]['activated'];
     }
 
diff --git a/lib/classes/SmileyFormat.php b/lib/classes/SmileyFormat.php
index 5b52df8..e0a9034 100644
--- a/lib/classes/SmileyFormat.php
+++ b/lib/classes/SmileyFormat.php
@@ -51,7 +51,7 @@ class SmileyFormat extends TextFormat
         $smileys = Smiley::getShort();
         $name    = $smileys[$matches[2]] ?? '';
         return $name
-            ? $matches[1] . Smiley::getByName($name)->getImageTag() . $matches[3]
+            ? $matches[1] . Smiley::getByName($name)->getImageTag() . ($matches[3] ?? '')
             : $matches[0];
     }
 }
diff --git a/lib/classes/WikiFormat.php b/lib/classes/WikiFormat.php
index 262ab65..0614010 100644
--- a/lib/classes/WikiFormat.php
+++ b/lib/classes/WikiFormat.php
@@ -99,7 +99,7 @@ class WikiFormat extends StudipFormat
                 $rule['start'],
                 $rule['end'],
                 $rule['callback'],
-                $rule['before'] ?: null
+                $rule['before'] ?? null
             );
         }
     }
diff --git a/lib/classes/calendar/CalendarScheduleModel.php b/lib/classes/calendar/CalendarScheduleModel.php
index 47b65c4..feb79d2 100644
--- a/lib/classes/calendar/CalendarScheduleModel.php
+++ b/lib/classes/calendar/CalendarScheduleModel.php
@@ -227,7 +227,7 @@ class CalendarScheduleModel
                         'title' => _("Dies ist eine vorgemerkte Veranstaltung")
                     ];
                 } else {
-                    $entry['color'] = $details['color'] ?: ($member->gruppe % 9 + 1);
+                    $entry['color'] = $details ? $details['color'] : ($member->gruppe % 9 + 1);
                 }
                 $entry['visible'] = $details ? $details['visible'] : 1;
 
diff --git a/lib/classes/htmlpurifier/HTMLPurifier_Injector_TransformLinks.php b/lib/classes/htmlpurifier/HTMLPurifier_Injector_TransformLinks.php
index 73e648b..59dccba 100644
--- a/lib/classes/htmlpurifier/HTMLPurifier_Injector_TransformLinks.php
+++ b/lib/classes/htmlpurifier/HTMLPurifier_Injector_TransformLinks.php
@@ -10,7 +10,7 @@ class HTMLPurifier_Injector_TransformLinks extends HTMLPurifier_Injector
 
     public function handleElement(&$token)
     {
-        if ($token->name === 'a' && $token->attr['class'] === 'link-intern') {
+        if ($token->name === 'a' && isset($token->attr['class']) && $token->attr['class'] === 'link-intern') {
             $token->attr['href'] = TransformInternalLinks($token->attr['href']);
         }
     }