MDL-79890 core: Update uses of array_keys with multiple params

These now call the newly minted `moodle_array_keys_filter` method.

course/lib.php

@@ -639,7 +639,7 @@ function course_add_cm_to_section($courseorid, $cmid, $sectionnum, $beforemod =
     $modarray = explode(",", trim($section->sequence));
     if (empty($section->sequence)) {
         $newsequence = "$cmid";
-    } else if ($beforemod && ($key = array_keys($modarray, $beforemod))) {
+    } else if ($beforemod && ($key = moodle_array_keys_filter($modarray, $beforemod))) {
         $insertarray = array($cmid, $beforemod);
         array_splice($modarray, $key[0], 1, $insertarray);
         $newsequence = implode(",", $modarray);
@@ -1111,7 +1111,7 @@ function delete_mod_from_section($modid, $sectionid) {
 
         $modarray = explode(",", $section->sequence);
 
-        if ($key = array_keys ($modarray, $modid)) {
+        if ($key = moodle_array_keys_filter($modarray, $modid)) {
             array_splice($modarray, $key[0], 1);
             $newsequence = implode(",", $modarray);
             $DB->set_field("course_sections", "sequence", $newsequence, array("id"=>$section->id));

files/classes/converter.php

@@ -165,7 +165,7 @@ public function poll_conversion(conversion $conversion) {
      */
     protected function get_next_converter($converters, $currentconverter = null) {
         if ($currentconverter) {
-            $keys = array_keys($converters, $currentconverter);
+            $keys = moodle_array_keys_filter($converters, $currentconverter);
             $key = $keys[0];
             if (isset($converters[$key + 1])) {
                 return $converters[$key + 1];

lib/grade/grade_category.php

@@ -1097,7 +1097,7 @@ public function aggregate_values_and_adjust_bounds($grade_values,
                 $freq = array_count_values($converted_grade_values);
                 arsort($freq);                      // sort by frequency keeping keys
                 $top = reset($freq);               // highest frequency count
-                $modes = array_keys($freq, $top);  // search for all modes (have the same highest count)
+                $modes = moodle_array_keys_filter($freq, $top);  // Search for all modes (have the same highest count).
                 rsort($modes, SORT_NUMERIC);       // get highest mode
                 $agg_grade = reset($modes);
                 // Record the weights as used.

lib/horde/framework/Horde/Imap/Client/Cache/Backend/Cache.php

@@ -143,7 +143,7 @@ public function save()
 
                     foreach (array_keys(array_flip($val['slice'])) as $slice) {
                         $data = array();
-                        foreach (array_keys($s['s'], $slice) as $uid) {
+                        foreach (moodle_array_keys_filter($s['s'], $slice) as $uid) {
                             $data[$uid] = is_array($d[$uid])
                                 ? serialize($d[$uid])
                                 : $d[$uid];
@@ -297,7 +297,7 @@ public function deleteMsgs($mailbox, $uids)
         foreach (array_unique($deleted) as $slice) {
             /* Get rid of slice if less than 10% of capacity. */
             if (($slice != $slicemap['i']) &&
-                ($slice_uids = array_keys($slicemap['s'], $slice)) &&
+                ($slice_uids = moodle_array_keys_filter($slicemap['s'], $slice)) &&
                 ($this->_params['slicesize'] * 0.1) > count($slice_uids)) {
                 $this->_toUpdate($mailbox, 'add', $slice_uids);
                 $this->_cache->expire($this->_getCid($mailbox, $slice));
@@ -416,7 +416,7 @@ protected function _loadSlice($mailbox, $slice)
             $ptr = &$this->_slicemap[$mailbox];
 
             // Slice data is corrupt; remove from slicemap.
-            foreach (array_keys($ptr['s'], $slice) as $val) {
+            foreach (moodle_array_keys_filter($ptr['s'], $slice) as $val) {
                 unset($ptr['s'][$val]);
             }
 

lib/horde/readme_moodle.txt

@@ -16,6 +16,8 @@ Description of import of Horde libraries
 Notes:
 * 2023-01-20 Applied patch https://github.com/horde/Util/pull/10
 * 2023-01-20 Horde/Mail is copied from https://github.com/bytestream/Mail/tree/v2.7.1 for PHP 8.1 compatibility
+* MDL-79890: Calls to array_keys() passing a second parameter have been modified to call `moodle_array_keys_filter` instead for PHP 8.3 compat.
+  This change is not fed upstream as Horde appears abandoned.
 
 ====
 #!/bin/sh

lib/listlib.php

@@ -628,7 +628,7 @@ public function image_spacer() {
      */
     public function create_children(&$records, &$children, $thisrecordid) {
         //keys where value is $thisrecordid
-        $thischildren = array_keys($children, $thisrecordid);
+        $thischildren = moodle_array_keys_filter($children, $thisrecordid);
         foreach ($thischildren as $child) {
             $thisclass = get_class($this);
             $newlistitem = new $thisclass($records[$child], $this->children, $this->attributes);

lib/moodlelib.php

@@ -11049,9 +11049,10 @@ function exceeds_password_length(string $password, int $pepperlength = 0): bool
  *
  * @param array $array
  * @param mixed $filter The value to filter on
+ * @param bool $strict Whether to apply a strit test with the filter
  * @return array
  */
-function moodle_array_keys_filter(array $array, mixed $filter, bool $strict): array {
+function moodle_array_keys_filter(array $array, mixed $filter, bool $strict = false): array {
     return array_keys(array_filter(
         $array,
         function($value, $key) use ($filter, $strict): bool {

mod/workshop/allocation/random/lib.php

@@ -702,7 +702,7 @@ protected function shuffle_assoc(&$array) {
     protected function filter_current_assessments(&$newallocations, $assessments) {
         foreach ($assessments as $assessment) {
             $allocation     = array($assessment->reviewerid => $assessment->authorid);
-            $foundat        = array_keys($newallocations, $allocation);
+            $foundat        = moodle_array_keys_filter($newallocations, $allocation);
             $newallocations = array_diff_key($newallocations, array_flip($foundat));
         }
     }

mod/workshop/eval/best/lib.php

@@ -183,7 +183,7 @@ protected function process_assessments(array $assessments, array $diminfo, stdcl
         }
 
         // identify the best assessments - that is those with the shortest distance from the best assessment
-        $bestids = array_keys($distances, min($distances));
+        $bestids = moodle_array_keys_filter($distances, min($distances));
 
         // for every assessment, calculate its distance from the nearest best assessment
         $distances = array();

question/format/blackboard_six/formatpool.php

@@ -446,7 +446,7 @@ public function process_matching($xml, &$questions) {
                     $choiceid = $this->getpath($choice,
                             array('@', 'id'), '', true);
                     $fiber = array_search($choiceid, $mappings);
-                    $fiber = array_keys ($mappings, $choiceid);
+                    $fiber = moodle_array_keys_filter($mappings, $choiceid);
                     foreach ($fiber as $correctanswerid) {
                         // We have found a correspondance for this choice so we need to take the associated answer.
                         foreach ($answers as $answer) {

question/format/blackboard_six/formatqti.php

@@ -837,7 +837,7 @@ public function process_matching($quest, &$questions) {
             if ($subanswertext != '') { // Only import non empty subanswers.
                 $subquestion = '';
 
-                $fiber = array_keys ($mappings, $choiceid);
+                $fiber = moodle_array_keys_filter($mappings, $choiceid);
                 foreach ($fiber as $correctanswerid) {
                     // We have found a correspondance for this subanswer so we need to take the associated subquestion.
                     foreach ($quest->RESPONSE_BLOCK->subquestions as $qid => $subq) {

question/type/ddwtos/edit_ddwtos_form.php

@@ -56,7 +56,7 @@ protected function choice_group($mform) {
 
     protected function extra_slot_validation(array $slots, array $choices): ?string {
         foreach ($slots as $slot) {
-            if (count(array_keys($slots, $slot)) > 1) {
+            if (count(array_filter($slots, fn($value) => $value == $slot)) > 1) {
                 $choice = $choices[$slot - 1];
                 if (!isset($choice['infinite']) || $choice['infinite'] != 1) {
                     return get_string('errorlimitedchoice', 'qtype_ddwtos',