transfer changeset 59563 from svn

30 files changed, 117 insertions, 90 deletions

diff --git a/app/controllers/calendar/schedule.php b/app/controllers/calendar/schedule.php
index c20fbea..b40c9dc 100644
--- a/app/controllers/calendar/schedule.php
+++ b/app/controllers/calendar/schedule.php
@@ -77,6 +77,7 @@ class Calendar_ScheduleController extends AuthenticatedController
             }
             Navigation::activateItem('/browse/my_courses/schedule');
         } else {
+            $institute_id = null;
             Navigation::activateItem('/calendar/schedule');
         }
 
diff --git a/app/controllers/contact.php b/app/controllers/contact.php
index ea46c82..b69944d 100644
--- a/app/controllers/contact.php
+++ b/app/controllers/contact.php
@@ -23,7 +23,7 @@ class ContactController extends AuthenticatedController
         $this->groups = SimpleCollection::createFromArray(Statusgruppen::findByRange_id(User::findCurrent()->id));
 
         // Load requested group
-        if ($args[0]) {
+        if (!empty($args[0])) {
             $this->group = $this->groups->findOneBy('statusgruppe_id', $args[0]);
 
             //Check for cheaters
@@ -76,6 +76,7 @@ class ContactController extends AuthenticatedController
             $selected = $this->group;
             $contacts = SimpleCollection::createFromArray(User::findMany($selected->members->pluck('user_id')));
         } else {
+            $selected = false;
             $contacts = User::findCurrent()->contacts;
         }
         $contacts = $contacts->filter(function($u) {
@@ -206,7 +207,7 @@ class ContactController extends AuthenticatedController
         $letterlist = new SidebarWidget();
         $html       = '';
         foreach (range('A', 'Z') as $letter) {
-            if ($this->contacts[$letter]) {
+            if (isset($this->contacts[$letter])) {
                 $html .= "<a href=\"#letter_{$letter}\">{$letter}</a>";
             } else {
                 $html .= "<span>{$letter}</span>";
diff --git a/app/controllers/search/courses.php b/app/controllers/search/courses.php
index cd38f94..fe8d729 100644
--- a/app/controllers/search/courses.php
+++ b/app/controllers/search/courses.php
@@ -34,7 +34,7 @@ class Search_CoursesController extends AuthenticatedController
             Navigation::activateItem('/search/courses/' . $this->nav_option);
         } else {
             URLHelper::removeLinkParam('option');
-            $level = Request::get('level', $_SESSION['sem_browse_data']['level']);
+            $level = Request::get('level', $_SESSION['sem_browse_data']['level'] ?? null);
             $default_option = SemBrowse::getSearchOptionNavigation('sidebar');
             if (!$level) {
                 PageLayout::setTitle(_($default_option->getTitle()));
diff --git a/app/controllers/search/globalsearch.php b/app/controllers/search/globalsearch.php
index 9c41112..b8de786 100644
--- a/app/controllers/search/globalsearch.php
+++ b/app/controllers/search/globalsearch.php
@@ -116,7 +116,7 @@ class Search_GlobalsearchController extends AuthenticatedController
     private function getSemesters()
     {
         // set the current semester as the initially selected semester
-        if (!$_SESSION['global_search']['selects']) {
+        if (empty($_SESSION['global_search']['selects'])) {
             $current_sem = GlobalSearchModule::getCurrentSemester();
             $_SESSION['global_search']['selects']['semester'] = $current_sem;
         }
diff --git a/app/controllers/search/module.php b/app/controllers/search/module.php
index dd555e0..57e24d3 100644
--- a/app/controllers/search/module.php
+++ b/app/controllers/search/module.php
@@ -119,12 +119,15 @@ class Search_ModuleController extends MVVController
             }
 
             if ($do_search) {
-                PageLayout::postInfo(sprintf(ngettext(
-                            '%s Modul gefunden für die Suche nach <em>%s</em>',
-                            '%s Module gefunden für die Suche nach <em>%s</em>',
-                            count($this->search_result['Modul'])),
-                            count($this->search_result['Modul']),
-                            htmlReady($this->sterm)));
+                PageLayout::postInfo(sprintf(
+                    ngettext(
+                        '%s Modul gefunden für die Suche nach <em>%s</em>',
+                        '%s Module gefunden für die Suche nach <em>%s</em>',
+                        count($this->search_result['Modul'])
+                    ),
+                    count($this->search_result['Modul']),
+                    htmlReady($this->sterm)
+                ));
             }
         }
 
@@ -147,14 +150,11 @@ class Search_ModuleController extends MVVController
         $sidebar->addWidget($widget, 'sem_filter');
 
         $this->input_search = $this->sterm;
-        $this->result_count = is_array($this->search_result['Modul']) ? count($this->search_result['Modul']) : 0;
-
-        $drill_down['studiengaenge']['objects'] =
-                $this->drilldown_studiengaenge($this->search_result['Modul']);
-        $drill_down['faecher']['objects'] =
-                $this->drilldown_faecher($this->search_result['Modul']);
-        $drill_down['institutes']['objects'] =
-                $this->drilldown_institutes($this->search_result['Modul']);
+        $this->result_count = is_array($this->search_result['Modul'] ?? null) ? count($this->search_result['Modul']) : 0;
+
+        $drill_down['studiengaenge']['objects'] = $this->drilldown_studiengaenge($this->search_result['Modul'] ?? null);
+        $drill_down['faecher']['objects'] = $this->drilldown_faecher($this->search_result['Modul'] ?? null);
+        $drill_down['institutes']['objects'] = $this->drilldown_institutes($this->search_result['Modul'] ?? null);
         if (count($drill_down['institutes']['objects'])
                 || count($drill_down['studiengaenge']['objects'])
                 || count($drill_down['faecher']['objects'])) {
@@ -214,8 +214,10 @@ class Search_ModuleController extends MVVController
         }
 
         $this->module = [];
-        if (is_array($this->search_result['Modul'])
-                && count($this->search_result['Modul'])) {
+        if (isset($this->search_result['Modul'])
+            && is_array($this->search_result['Modul'])
+            && count($this->search_result['Modul'])
+        ) {
             if (!empty($this->drill_down_type) && !empty($this->drill_down_id)) {
                 $this->search_result['Modul'] = $this->filter_modules(
                         $this->search_result['Modul'], $this->drill_down_type, $this->drill_down_id);
diff --git a/app/controllers/search/studiengaenge.php b/app/controllers/search/studiengaenge.php
index 94399fc..92d00f6 100644
--- a/app/controllers/search/studiengaenge.php
+++ b/app/controllers/search/studiengaenge.php
@@ -197,7 +197,7 @@ class Search_StudiengaengeController extends MVVController
             $this->sessSet('selected_semester', $sem);
         }
 
-        $this->with_courses = Request::option('with_courses', ($_SESSION['MVV_SEARCH_SEQUENCE_WITH_COURSES'] ?: null));
+        $this->with_courses = Request::option('with_courses', $_SESSION['MVV_SEARCH_SEQUENCE_WITH_COURSES'] ?? null);
         $_SESSION['MVV_SEARCH_SEQUENCE_WITH_COURSES'] = $this->with_courses;
 
         $studiengangTeil = StudiengangTeil::find($stgteil_id);
@@ -230,7 +230,7 @@ class Search_StudiengaengeController extends MVVController
             } else {
                 $this->active_sem = Semester::find($this->sessGet('selected_semester', Semester::findCurrent()->id));
             }
-            $this->active_sem = $this->semesters[$this->active_sem->id] ? $this->active_sem : null;
+            $this->active_sem = isset($this->semesters[$this->active_sem->id]) ? $this->active_sem : null;
             if (!$this->active_sem && count($this->semesters)) {
                 $active_sem = reset($this->semesters);
                 $this->active_sem = Semester::find($active_sem['semester_id']);
diff --git a/app/views/blubber/index.php b/app/views/blubber/index.php
index 0daceb6..0394805 100644
--- a/app/views/blubber/index.php
+++ b/app/views/blubber/index.php
@@ -1,7 +1,7 @@
 <div class="blubber_panel"
      data-active_thread="<?= htmlReady($thread->getId()) ?>"
      data-thread_data="<?= htmlReady(json_encode($thread_data ?: ['thread_posting' => []])) ?>"
-     data-threads_more_down="<?= htmlReady($threads_more_down) ?>"
+     data-threads_more_down="<?= htmlReady($threads_more_down ?? '') ?>"
      :class="waiting ? 'waiting' : ''">
 
     <div id="blubber_stream_container">
diff --git a/app/views/score/index.php b/app/views/score/index.php
index 55c55be..91f352e 100644
--- a/app/views/score/index.php
+++ b/app/views/score/index.php
@@ -51,7 +51,7 @@
             $content = Assets::img('blank.gif', ['width' => 16]) . ' ';
 
             // News
-            if ($news = $person['newscount']) {
+            if ($news = ($person['newscount'] ?? false)) {
                 $tmp = sprintf(ngettext('Eine persönliche Ankündigung', '%s persönliche Ankündigungen', $news), $news);
                 $content .= sprintf(
                     '<a href="%s">%s</a> ',
@@ -63,7 +63,7 @@
             }
 
             // Votes
-            if ($vote = $person['votecount']) {
+            if ($vote = ($person['votecount'] ?? false)) {
                 $tmp = sprintf(ngettext('Eine Umfrage', '%s Umfragen', $vote), $vote);
                 $content .= sprintf(
                     '<a href="%s">%s</a> ',
@@ -75,7 +75,7 @@
             }
 
             // Termine
-            if ($termin = $person['eventcount']) {
+            if ($termin = ($person['eventcount'] ?? false)) {
                 $tmp = sprintf(ngettext('Ein Termin', '%s Termine', $termin), $termin);
                 $content .= sprintf(
                     '<a href="%s">%s</a> ',
diff --git a/app/views/search/breadcrumb.php b/app/views/search/breadcrumb.php
index da6c3717..f4b19d7 100644
--- a/app/views/search/breadcrumb.php
+++ b/app/views/search/breadcrumb.php
@@ -3,9 +3,9 @@
 <? $sum_points = count($bc_points) - 1; ?>
 <? $index = 0; ?>
 <? foreach($bc_points as $type => $point):?>
-    <? $id2 = reset(array_values((array) $point['add'])); ?>
-    <? $link = $controller->link_for('/' . $point['actn'], $point['id'], $id2); ?>
-    <? if (is_array($point['add'])) : ?>
+    <? $id2 = isset($point['add']) ? reset(array_values((array) $point['add'])) : null; ?>
+    <? $link = $controller->link_for('/' . $point['actn'], $point['id'] ?? null, $id2); ?>
+    <? if (isset($point['add']) && is_array($point['add'])) : ?>
         <? $mvv_object = $type::find($point['id']); ?>
         <? if ($mvv_object && $type == 'Fach' && $additional_object = Abschluss::find($point['add']['Abschluss'])) : ?>
             <a href="<?= $link ?>"><?= htmlReady($mvv_object->getDisplayName() . ' (' . $additional_object->name . ')') ?></a>
@@ -16,7 +16,7 @@
     <? else : ?>
         <? if ($type == 'StudiengangTeil' && $mvv_object = $type::find($point['id'])) : ?>
             <a href="<?= $link ?>"><?= htmlReady($mvv_object->getDisplayName(ModuleManagementModel::DISPLAY_FACH)) ?></a>
-        <? elseif ($point['id'] && $mvv_object = $type::find($point['id'])) : ?>
+        <? elseif (!empty($point['id']) && $mvv_object = $type::find($point['id'])) : ?>
             <a href="<?= $link ?>"><?= htmlReady($mvv_object->getDisplayName(0)) ?></a>
         <? else : ?>
             <a href="<?= $link ?>"><?= htmlReady($point['name']) ?></a>
diff --git a/app/views/search/module/index.php b/app/views/search/module/index.php
index d0b5353..4c56fda 100644
--- a/app/views/search/module/index.php
+++ b/app/views/search/module/index.php
@@ -13,7 +13,7 @@
 <!-- Trefferset -->
 <table class="default collapsable">
     <caption>
-        <? if ($count) : ?>
+    <? if (isset($count)) : ?>
         <?= sprintf(_('Gefundene Module für <i>%s</i>'), htmlReady($sterm)) ?>
         <span class="actions">
             <? printf(ngettext('%s Modul', '%s Module', $count), $count); ?>
diff --git a/app/views/search/studiengaenge/verlauf.php b/app/views/search/studiengaenge/verlauf.php
index b930696..8917e24 100644
--- a/app/views/search/studiengaenge/verlauf.php
+++ b/app/views/search/studiengaenge/verlauf.php
@@ -6,7 +6,7 @@
     <table class="mvv-modul-details default nohover">
         <caption>
             <?= htmlReady($studiengangTeilName) ?>
-    <? if ($studiengang && $stgTeilBez) : ?>
+    <? if ($studiengang && !empty($stgTeilBez)) : ?>
         <h3>
             <?= sprintf(_('%s im Studiengang %s'), htmlReady($stgTeilBez->getDisplayName()), htmlReady($studiengang->getDisplayName(ModuleManagementModel::DISPLAY_ABSCHLUSS))) ?>
             <? if (Config::get()->ENABLE_STUDYCOURSE_INFO_PAGE) : ?>
diff --git a/lib/classes/BlubberFormat.php b/lib/classes/BlubberFormat.php
index 4a52286..b8f2286 100644
--- a/lib/classes/BlubberFormat.php
+++ b/lib/classes/BlubberFormat.php
@@ -79,9 +79,9 @@ class BlubberFormat extends StudipFormat
             $this->addMarkup(
                 $name,
                 $rule['start'],
-                $rule['end'],
-                $rule['callback'],
-                $rule['before'] ?: null
+                $rule['end'] ?? null,
+                $rule['callback'] ?? null,
+                $rule['before'] ?? null
             );
         }
     }
diff --git a/lib/classes/BreadCrumb.class.php b/lib/classes/BreadCrumb.class.php
index 386da4f..1848df1 100644
--- a/lib/classes/BreadCrumb.class.php
+++ b/lib/classes/BreadCrumb.class.php
@@ -66,9 +66,11 @@ class BreadCrumb
         $newTrail = [];
         $lastElement = false;
         foreach ($trail as $key => $trail_item) {
-            if ($lastElement) break;
+            if ($lastElement) {
+                break;
+            }
             $newTrail[$key] = $trail_item;
-            $lastElement = $key === $id;
+            $lastElement = isset($id) && $key === $id;
         }
         $this->trail = $newTrail;
     }
diff --git a/lib/classes/Config.class.php b/lib/classes/Config.class.php
index f5afaab..b04fc75 100644
--- a/lib/classes/Config.class.php
+++ b/lib/classes/Config.class.php
@@ -115,7 +115,7 @@ class Config implements ArrayAccess, Countable, IteratorAggregate
      */
     public function getMetadata($field)
     {
-        return $this->metadata[$field];
+        return $this->metadata[$field] ?? false;
     }
 
     /**
diff --git a/lib/classes/MultiPersonSearch.class.php b/lib/classes/MultiPersonSearch.class.php
index 65cad48..3ac408e 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'] ?? [];
     }
 
     /**
diff --git a/lib/classes/RangeConfig.class.php b/lib/classes/RangeConfig.class.php
index fc90434..a1e1bb9 100644
--- a/lib/classes/RangeConfig.class.php
+++ b/lib/classes/RangeConfig.class.php
@@ -175,7 +175,7 @@ class RangeConfig extends Config
 
         // Otherwise convert it to an appropriate format and store it
         $metadata = Config::get()->getMetadata($field);
-        $entry->value = $this->convertForDatabase($metadata['type'], $value, $field);
+        $entry->value = $this->convertForDatabase($metadata['type'] ?? 'string', $value, $field);
 
         $ret = $entry->store();
         if ($ret) {
diff --git a/lib/classes/SQLQuery.php b/lib/classes/SQLQuery.php
index a6539fb..2904fc1 100755
--- a/lib/classes/SQLQuery.php
+++ b/lib/classes/SQLQuery.php
@@ -95,12 +95,12 @@ class SQLQuery
             unset($this->settings['where'][$name]);
         } elseif ($parameter === null && $condition !== null) {
             $this->settings['where'][$name] = $name;
-            $this->settings['parameter'] = array_merge((array) $this->settings['parameter'], $condition);
+            $this->settings['parameter'] = array_merge((array) ($this->settings['parameter'] ?? []), $condition);
         } elseif ($condition === null)  {
             $this->settings['where'][md5($name)] = $name;
         } else {
             $this->settings['where'][$name] = $condition;
-            $this->settings['parameter'] = array_merge((array) $this->settings['parameter'], $parameter);
+            $this->settings['parameter'] = array_merge((array) ($this->settings['parameter'] ?? []), $parameter);
         }
         return $this;
     }
@@ -218,7 +218,7 @@ class SQLQuery
             $sql = "SELECT `{$this->settings['table']}`.* ";
         }
 
-        foreach ((array) $this->settings['select'] as $alias => $statement) {
+        foreach ((array) ($this->settings['select'] ?? []) as $alias => $statement) {
             $sql .= $statement ? "{$statement} AS {$alias} " : $alias;
         }
 
@@ -268,25 +268,27 @@ class SQLQuery
     protected function getQuery()
     {
         $sql = "FROM `{$this->settings['table']}` ";
+        if (isset($this->settings['joins']) && is_array($this->settings['joins'])) {
         foreach ($this->settings['joins'] as $alias => $joindata) {
             $table = isset($joindata['table']) ? "{$joindata['table']} AS {$alias}" : $alias;
             $on = isset($joindata['on']) ? " ON ({$joindata['on']})" : '';
-            $sql .= " " . (isset($joindata['join']) ? $joindata['join'] : 'INNER JOIN') . " {$table}{$on} ";
+                $sql .= " " . ($joindata['join'] ?? 'INNER JOIN') . " {$table}{$on} ";
+            }
         }
-        if ($this->settings['where']) {
+        if (isset($this->settings['where'])) {
             $sql .= "WHERE (" . implode(") AND (", $this->settings['where']) . ") ";
         }
-        if ($this->settings['groupby']) {
+        if (isset($this->settings['groupby'])) {
             $sql .= "GROUP BY {$this->settings['groupby']} ";
         }
-        if ($this->settings['having']) {
+        if (isset($this->settings['having'])) {
             $sql .= "HAVING (" . implode(") AND (", $this->settings['having']) . ") ";
         }
 
-        if ($this->settings['order']) {
+        if (isset($this->settings['order'])) {
             $sql .= "ORDER BY {$this->settings['order']} ";
         }
-        if ($this->settings['limit']) {
+        if (isset($this->settings['limit']) && is_array($this->settings['limit'])) {
             $sql .= "LIMIT ". (int) $this->settings['limit'][0] . ", " . (int) $this->settings['limit'][1] . " ";
         }
         return $sql;
diff --git a/lib/classes/Score.class.php b/lib/classes/Score.class.php
index 515484b..3376a36 100644
--- a/lib/classes/Score.class.php
+++ b/lib/classes/Score.class.php
@@ -166,11 +166,11 @@ class Score
         $statements = [];
         foreach (self::getActivityTables() as $table) {
             $statements[] = "SELECT "
-                . ($table['date_column'] ?: 'mkdate')
+                . ($table['date_column'] ?? 'mkdate')
                 . " AS mkdate FROM "
                 . $table['table']
                 . " WHERE "
-                . ($table['user_id_column'] ?: 'user_id')
+                . ($table['user_id_column'] ?? 'user_id')
                 . " = :user "
                 . (!empty($table['where']) ? (' AND ' . $table['where']) : '');
         }
diff --git a/lib/classes/SemClass.class.php b/lib/classes/SemClass.class.php
index 6b885f1..bb63a80 100644
--- a/lib/classes/SemClass.class.php
+++ b/lib/classes/SemClass.class.php
@@ -217,7 +217,7 @@ class SemClass implements ArrayAccess
      */
     public function getModuleMetadata($modulename)
     {
-        return $this->data['modules'][$modulename];
+        return $this->data['modules'][$modulename] ?? false;
     }
 
     /**
@@ -310,8 +310,8 @@ class SemClass implements ArrayAccess
     public function isModuleAllowed($modulename)
     {
         return !isset($this->data['modules'][$modulename])
-            || !$this->data['modules'][$modulename]['sticky']
-            ||  $this->data['modules'][$modulename]['activated'];
+            || empty($this->data['modules'][$modulename]['sticky'])
+            || !empty($this->data['modules'][$modulename]['activated']);
     }
 
     /**
@@ -322,8 +322,8 @@ class SemClass implements ArrayAccess
     public function isModuleMandatory($module)
     {
         return isset($this->data['modules'][$module])
-            && $this->data['modules'][$module]['sticky']
-            && $this->data['modules'][$module]['activated'];
+            && !empty($this->data['modules'][$module]['sticky'])
+            && !empty($this->data['modules'][$module]['activated']);
     }
 
     public function getSemTypes()
diff --git a/lib/classes/StudipCoreFormat.php b/lib/classes/StudipCoreFormat.php
index 665bb37..e82670f 100644
--- a/lib/classes/StudipCoreFormat.php
+++ b/lib/classes/StudipCoreFormat.php
@@ -526,10 +526,10 @@ class StudipCoreFormat extends TextFormat
      */
     protected static function markupMedia($markup, $matches)
     {
-        $tag = $matches[1];
-        $params = explode(":",$matches[2]);
-        $url = $matches[3];
-        $whitespace = $matches[4];
+        $tag = $matches[1] ?? null;
+        $params = explode(':', $matches[2] ?? '');
+        $url = $matches[3] ?? null;
+        $whitespace = $matches[4] ?? null;
 
         foreach ($params as $key => $param) {
             if ($param) {
@@ -556,6 +556,8 @@ class StudipCoreFormat extends TextFormat
 
         $url = TransformInternalLinks($url);
         $pu = @parse_url($url);
+        $pu['first_target'] = false;
+        $intern = false;
         if (($pu['scheme'] == 'http' || $pu['scheme'] == 'https')
                 && ($pu['host'] == $_SERVER['HTTP_HOST'] || $pu['host'].':'.$pu['port'] == $_SERVER['HTTP_HOST'])
                 && mb_strpos($pu['path'], $GLOBALS['CANONICAL_RELATIVE_PATH_STUDIP']) === 0) {
@@ -563,8 +565,6 @@ class StudipCoreFormat extends TextFormat
             $checkpath = urldecode(mb_substr($pu['path'], mb_strlen($GLOBALS['CANONICAL_RELATIVE_PATH_STUDIP'])));
             if (mb_strpos($checkpath, '../') === false) {
                 list($pu['first_target']) = explode('/', $checkpath);
-            } else {
-                $pu['first_target'] = false;
             }
         }
         $LOAD_EXTERNAL_MEDIA = Config::GetInstance()->getValue('LOAD_EXTERNAL_MEDIA');
@@ -598,8 +598,8 @@ class StudipCoreFormat extends TextFormat
             $media = sprintf($format_strings[$tag],
                 $media_url,
                 isset($width) ? "width: ".$width."px;" : "",
-                $title,
-                $title
+                $title ?? '',
+                $title ?? ''
             );
         }
 
@@ -608,14 +608,14 @@ class StudipCoreFormat extends TextFormat
             $media = str_replace('<audio ', '<audio id="' . $random_id . '" onerror="STUDIP.Audio.handle(this);" ', $media);
         }
 
-        if ($link && $tag === "img") {
+        if (isset($link) && $tag === "img") {
             $media = sprintf('<a href="%s"%s>%s</a>',
                 $link,
                 !isLinkIntern($link) ? ' target="_blank" rel="noreferrer noopener"' : "",
                 $media
             );
         }
-        if ($position) {
+        if (isset($position)) {
             $media = '<div style="text-align: '.$position.'">'.$media.'</div>';
         }
         $media .= $whitespace;
diff --git a/lib/classes/StudipRangeTree.class.php b/lib/classes/StudipRangeTree.class.php
index 2dea8a0..fb22614 100644
--- a/lib/classes/StudipRangeTree.class.php
+++ b/lib/classes/StudipRangeTree.class.php
@@ -42,6 +42,8 @@ class StudipRangeTree extends TreeAbstract {
 
     var $sem_dates;
 
+    protected $entries_init_done = false;
+
     /**
     * constructor
     *
@@ -186,9 +188,12 @@ class StudipRangeTree extends TreeAbstract {
     }
 
     function getNumEntries($item_id, $num_entries_from_kids = false){
-        if (!$this->tree_data[$item_id])
+        if (!$this->tree_data[$item_id]) {
             return false;
-        if (!$this->entries_init_done) $this->initEntries();
+        }
+        if (!$this->entries_init_done) {
+            $this->initEntries();
+        }
 
         return parent::getNumEntries($item_id, $num_entries_from_kids);
     }
diff --git a/lib/classes/TreeAbstract.class.php b/lib/classes/TreeAbstract.class.php
index a23c494..846d27d 100644
--- a/lib/classes/TreeAbstract.class.php
+++ b/lib/classes/TreeAbstract.class.php
@@ -206,7 +206,10 @@ class TreeAbstract {
     */
     public function getKids($item_id)
     {
-        return (is_array($this->tree_childs[$item_id])) ? $this->tree_childs[$item_id] : null;
+        if (!isset($this->tree_childs[$item_id]) || !is_array($this->tree_childs[$item_id])) {
+            return null;
+        }
+        return $this->tree_childs[$item_id];
     }
 
     /**
@@ -219,7 +222,7 @@ class TreeAbstract {
     public function getNumKids($item_id)
     {
         if(!isset($this->tree_num_childs[$item_id])){
-            $this->tree_num_childs[$item_id] = (is_array($this->tree_childs[$item_id])) ? count($this->tree_childs[$item_id]) : 0;
+            $this->tree_num_childs[$item_id] = count($this->getKids($item_id) ?? []);
         }
         return $this->tree_num_childs[$item_id];
     }
diff --git a/lib/classes/calendar/CalendarScheduleModel.php b/lib/classes/calendar/CalendarScheduleModel.php
index 20f66c5..b3f8db6 100644
--- a/lib/classes/calendar/CalendarScheduleModel.php
+++ b/lib/classes/calendar/CalendarScheduleModel.php
@@ -221,13 +221,13 @@ class CalendarScheduleModel
                 $details = $stmt->fetch();
 
                 if ($entry['type'] == 'virtual') {
-                    $entry['color'] = $details['color'] ? $details['color'] : DEFAULT_COLOR_VIRTUAL;
+                    $entry['color'] = ($details && $details['color']) ? $details['color'] : DEFAULT_COLOR_VIRTUAL;
                     $entry['icons'][] = [
                         'image' => 'virtual.png',
                         'title' => _("Dies ist eine vorgemerkte Veranstaltung")
                     ];
                 } else {
-                    $entry['color'] = $details['color'] ?: ($member->gruppe % 9 + 1);
+                    $entry['color'] = ($details && $details['color']) ? $details['color'] : ($member->gruppe % 9 + 1);
                 }
                 $entry['visible'] = $details ? $details['visible'] : 1;
 
@@ -789,7 +789,7 @@ class CalendarScheduleModel
 
         $view = new CalendarWeekView($entries, 'schedule');
 
-        $view->setHeight(40 + (20 * $schedule_settings['zoom']));
+        $view->setHeight(40 + 20 * ($schedule_settings['zoom'] ?? 0));
         $view->setRange($schedule_settings['glb_start_time'], $schedule_settings['glb_end_time']);
         $view->setInsertFunction("function (entry, column, hour, end_hour) {
             STUDIP.Schedule.newEntry(entry, column, hour, end_hour)
diff --git a/lib/models/BlubberThread.php b/lib/models/BlubberThread.php
index 0be5cd2..e473717 100644
--- a/lib/models/BlubberThread.php
+++ b/lib/models/BlubberThread.php
@@ -48,7 +48,7 @@ class BlubberThread extends SimpleORMap implements PrivacyObject
     }
 
     public static $mention_thread_id = null;
-    protected $last_visit = null;
+    protected $last_visit = [];
 
     /**
      * Pre-Markup rule. Recognizes mentions in blubber as @username or @"Firstname lastname"
@@ -921,9 +921,8 @@ class BlubberThread extends SimpleORMap implements PrivacyObject
             'user_id' => $user_id,
             'html_id' => "blubberthread_".$this->getId()
         ]);
-        $this->last_visit[$user_id] = !$this->last_visit[$user_id]
-            ? object_get_visit($this->getId(), "blubberthread", "last", "", $user_id)
-            : $this->last_visit[$user_id];
+        $this->last_visit[$user_id] = $this->last_visit[$user_id]
+                                   ?? object_get_visit($this->getId(), 'blubberthread', 'last', '', $user_id);
         UserConfig::get($user_id)->store("BLUBBERTHREAD_VISITED_".$this->getId(), time());
     }
 
@@ -955,7 +954,13 @@ class BlubberThread extends SimpleORMap implements PrivacyObject
             }
 
             foreach ($matches[1] as $tag) {
-                $hashtags[mb_strtolower($tag)] += 1;
+                $tag = mb_strtolower($tag);
+
+                if (!isset($hashtags[$tag])) {
+                    $hashtags[$tag] = 0;
+                }
+
+                $hashtags[$tag] += 1;
             }
         }
         asort($hashtags);
diff --git a/lib/models/SimpleCollection.class.php b/lib/models/SimpleCollection.class.php
index 4d98087..f001106 100644
--- a/lib/models/SimpleCollection.class.php
+++ b/lib/models/SimpleCollection.class.php
@@ -684,7 +684,7 @@ class SimpleCollection extends StudipArrayObject
 
         $func = function ($d1, $d2) use ($sorter, $sort_func, $sort_locale) {
             do {
-                list($field, $dir) = current($sorter);
+                @list($field, $dir) = current($sorter);
                 if (!$sort_locale) {
                     $value1 = $d1[$field];
                     $value2 = $d2[$field];
@@ -693,7 +693,9 @@ class SimpleCollection extends StudipArrayObject
                     $value2 = static::translitLatin1(mb_substr($d2[$field], 0, 100));
                 }
                 $ret = $sort_func($value1, $value2);
-                if (strtolower($dir) == 'desc') $ret = $ret * -1;
+                if (strtolower($dir) === 'desc') {
+                    $ret = $ret * -1;
+                }
             } while ($ret === 0 && next($sorter));
 
             return $ret;
diff --git a/lib/models/SimpleORMap.class.php b/lib/models/SimpleORMap.class.php
index 75df771..7245490 100644
--- a/lib/models/SimpleORMap.class.php
+++ b/lib/models/SimpleORMap.class.php
@@ -822,6 +822,7 @@ class SimpleORMap implements ArrayAccess, Countable, IteratorAggregate
      */
     public static function __callStatic($name, $arguments)
     {
+        $order = '';
         $db_table = static::config('db_table');
         $alias_fields = static::config('alias_fields');
         $db_fields = static::config('db_fields');
@@ -1036,17 +1037,17 @@ class SimpleORMap implements ArrayAccess, Countable, IteratorAggregate
         }
         if ($type === 'has_and_belongs_to_many') {
             $thru_table = $options['thru_table'];
-            if (!$options['thru_key']) {
+            if (!isset($options['thru_key'])) {
                 $options['thru_key'] = $this->pk[0];
             }
-            if (!$options['thru_assoc_key'] || !$options['assoc_foreign_key']) {
+            if (!isset($options['thru_assoc_key']) || !isset($options['assoc_foreign_key'])) {
                 $class = $options['class_name'];
                 $record = new $class();
                 $meta = $record->getTableMetadata();
-                if (!$options['thru_assoc_key'] ) {
+                if (!isset($options['thru_assoc_key'])) {
                     $options['thru_assoc_key'] = $meta['pk'][0];
                 }
-                if (!$options['assoc_foreign_key']) {
+                if (!isset($options['assoc_foreign_key'])) {
                     $options['assoc_foreign_key']= $meta['pk'][0];
                 }
             }
@@ -1818,6 +1819,7 @@ class SimpleORMap implements ArrayAccess, Countable, IteratorAggregate
         if ($this->applyCallbacks('before_store') === false) {
             return false;
         }
+        $ret = 0;
         if (!$this->isDeleted() && ($this->isDirty() || $this->isNew())) {
             if ($this->isNew()) {
                 if ($this->applyCallbacks('before_create') === false) {
@@ -2142,7 +2144,7 @@ class SimpleORMap implements ArrayAccess, Countable, IteratorAggregate
             } else {
                 $p = (array)$params($this);
                 $records = call_user_func_array($to_call, count($p) ? $p : [null]);
-                $result = is_array($records) ? $records[0] : $records;
+                $result = is_array($records) ? ($records[0] ?? null) : $records;
                 $this->relations[$relation] = $result;
             }
         }
diff --git a/lib/models/resources/Room.class.php b/lib/models/resources/Room.class.php
index e5960db..59c06fd 100644
--- a/lib/models/resources/Room.class.php
+++ b/lib/models/resources/Room.class.php
@@ -40,7 +40,7 @@ class Room extends Resource
 
     protected static function configure($config = [])
     {
-        if (!is_array($config['additional_fields'])) {
+        if (!isset($config['additional_fields']) || !is_array($config['additional_fields'])) {
             $config['additional_fields'] = [];
         }
         foreach (self::$required_properties as $property) {
diff --git a/lib/object.inc.php b/lib/object.inc.php
index f7bcf90..c0c4e15 100644
--- a/lib/object.inc.php
+++ b/lib/object.inc.php
@@ -104,7 +104,7 @@ function object_get_visit($object_id, $plugin_id, $mode = "last", $open_object_i
         $cache[$object_id][$plugin_id][$user_id] = null;
     }
 
-    if ($cache[$object_id][$plugin_id][$user_id]) {
+    if (isset($cache[$object_id][$plugin_id][$user_id])) {
         return $mode == 'last'
              ? $cache[$object_id][$plugin_id][$user_id]['last_visitdate']
              : $cache[$object_id][$plugin_id][$user_id]['visitdate'];
diff --git a/lib/user_visible.inc.php b/lib/user_visible.inc.php
index cf0da1c..c7b07f0 100644
--- a/lib/user_visible.inc.php
+++ b/lib/user_visible.inc.php
@@ -119,6 +119,8 @@ function get_vis_query($table_alias = 'auth_user_md5', $context = '') {
         $context_default = (int) Config::get()->getValue(mb_strtoupper($context) . '_VISIBILITY_DEFAULT');
         $contextQuery = " AND (IFNULL(user_visibility.{$context}, {$context_default}) = 1
                                OR {$table_alias}.visible = 'always')";
+    } else {
+        $contextQuery = '';
     }
 
     $my_domains = UserDomain::getUserDomainsForUser($GLOBALS['user']->id);
diff --git a/lib/visual.inc.php b/lib/visual.inc.php
index e6a66b5..4dc1127 100644
--- a/lib/visual.inc.php
+++ b/lib/visual.inc.php
@@ -311,9 +311,9 @@ function isLinkIntern($url) {
         return true;
     }
 
-    return in_array($pum['scheme'], ['https', 'http', NULL], true)
-        && in_array($pum['host'], [$_SERVER['SERVER_NAME'], NULL], true)
-        && in_array($pum['port'], [$_SERVER['SERVER_PORT'], NULL], true)
+    return in_array($pum['scheme'] ?? null, ['https', 'http', null], true)
+        && in_array($pum['host'] ?? null, [$_SERVER['SERVER_NAME'], null], true)
+        && in_array($pum['port'] ?? null, [$_SERVER['SERVER_PORT'], null], true)
         && mb_strpos($pum['path'], $GLOBALS['CANONICAL_RELATIVE_PATH_STUDIP']) === 0;
 }