diff --git a/mod/forum/externallib.php b/mod/forum/externallib.php
index 94b10b98c1f..2956639613d 100644
--- a/mod/forum/externallib.php
+++ b/mod/forum/externallib.php
@@ -2245,7 +2245,7 @@ class mod_forum_external extends external_api {
             $parentposts = [];
             if ($parentids) {
                 $parentposts = $postbuilder->build(
-                    $user,
+                    $USER,
                     [$forum],
                     [$discussion],
                     $postvault->get_from_ids(array_values($parentids))
@@ -2261,7 +2261,7 @@ class mod_forum_external extends external_api {
                 'timecreated' => $firstpost->get_time_created(),
                 'authorfullname' => $discussionauthor->get_full_name(),
                 'posts' => [
-                    'userposts' => $postbuilder->build($user, [$forum], [$discussion], $posts),
+                    'userposts' => $postbuilder->build($USER, [$forum], [$discussion], $posts),
                     'parentposts' => $parentposts,
                 ],
             ];
diff --git a/mod/forum/tests/externallib_test.php b/mod/forum/tests/externallib_test.php
index 0ce852f0af0..2430f272e58 100644
--- a/mod/forum/tests/externallib_test.php
+++ b/mod/forum/tests/externallib_test.php
@@ -2611,6 +2611,7 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
      * Test get forum posts by user id.
      */
     public function test_mod_forum_get_discussion_posts_by_userid() {
+        global $DB;
         $this->resetAfterTest(true);
 
         $urlfactory = mod_forum\local\container::get_url_factory();
@@ -2722,9 +2723,20 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
 
         // Following line enrol and assign default role id to the user.
         // So the user automatically gets mod/forum:viewdiscussion on all forums of the course.
-        $this->getDataGenerator()->enrol_user($user1->id, $course1->id);
+        $this->getDataGenerator()->enrol_user($user1->id, $course1->id, 'teacher');
         $this->getDataGenerator()->enrol_user($user2->id, $course1->id);
-
+        // Changed display period for the discussions in past.
+        $time = time();
+        $discussion = new \stdClass();
+        $discussion->id = $discussion1->id;
+        $discussion->timestart = $time - 200;
+        $discussion->timeend = $time - 100;
+        $DB->update_record('forum_discussions', $discussion);
+        $discussion = new \stdClass();
+        $discussion->id = $discussion2->id;
+        $discussion->timestart = $time - 200;
+        $discussion->timeend = $time - 100;
+        $DB->update_record('forum_discussions', $discussion);
         // Create what we expect to be returned when querying the discussion.
         $expectedposts = array(
             'discussions' => array(),
@@ -2773,34 +2785,36 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
                             'view' => true,
                             'edit' => true,
                             'delete' => true,
-                            'split' => false,
+                            'split' => true,
                             'reply' => true,
                             'export' => false,
                             'controlreadstatus' => false,
-                            'canreplyprivately' => false,
+                            'canreplyprivately' => true,
                             'selfenrol' => false
                         ],
                         'urls' => [
                             'view' => $urlfactory->get_view_post_url_from_post_id(
-                                    $discussion1reply1->discussion, $discussion1reply1->id)->out(false),
+                                $discussion1reply1->discussion, $discussion1reply1->id)->out(false),
                             'viewisolated' => $isolatedurluser->out(false),
                             'viewparent' => $urlfactory->get_view_post_url_from_post_id(
-                                    $discussion1reply1->discussion, $discussion1reply1->parent)->out(false),
+                                $discussion1reply1->discussion, $discussion1reply1->parent)->out(false),
                             'edit' => (new moodle_url('/mod/forum/post.php', [
-                                    'edit' => $discussion1reply1->id
+                                'edit' => $discussion1reply1->id
                             ]))->out(false),
                             'delete' => (new moodle_url('/mod/forum/post.php', [
-                                    'delete' => $discussion1reply1->id
+                                'delete' => $discussion1reply1->id
+                            ]))->out(false),
+                            'split' => (new moodle_url('/mod/forum/post.php', [
+                                'prune' => $discussion1reply1->id
                             ]))->out(false),
-                            'split' => null,
                             'reply' => (new moodle_url('/mod/forum/post.php#mformforum', [
-                                    'reply' => $discussion1reply1->id
+                                'reply' => $discussion1reply1->id
                             ]))->out(false),
                             'export' => null,
                             'markasread' => null,
                             'markasunread' => null,
                             'discuss' => $urlfactory->get_discussion_view_url_from_discussion_id(
-                                    $discussion1reply1->discussion)->out(false),
+                                $discussion1reply1->discussion)->out(false),
                         ],
                     ]
                 ],
@@ -2833,13 +2847,13 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
                         'charcount' => null,
                         'capabilities' => [
                             'view' => true,
-                            'edit' => false,
-                            'delete' => false,
+                            'edit' => true,
+                            'delete' => true,
                             'split' => false,
                             'reply' => true,
                             'export' => false,
                             'controlreadstatus' => false,
-                            'canreplyprivately' => false,
+                            'canreplyprivately' => true,
                             'selfenrol' => false
                         ],
                         'urls' => [
@@ -2847,8 +2861,12 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
                                 $discussion1firstpostobject->discussion, $discussion1firstpostobject->id)->out(false),
                             'viewisolated' => $isolatedurlparent->out(false),
                             'viewparent' => null,
-                            'edit' => null,
-                            'delete' => null,
+                            'edit' => (new moodle_url('/mod/forum/post.php', [
+                                'edit' => $discussion1firstpostobject->id
+                            ]))->out(false),
+                            'delete' => (new moodle_url('/mod/forum/post.php', [
+                                'delete' => $discussion1firstpostobject->id
+                            ]))->out(false),
                             'split' => null,
                             'reply' => (new moodle_url('/mod/forum/post.php#mformforum', [
                                 'reply' => $discussion1firstpostobject->id
@@ -2906,11 +2924,11 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
                             'view' => true,
                             'edit' => true,
                             'delete' => true,
-                            'split' => false,
+                            'split' => true,
                             'reply' => true,
                             'export' => false,
                             'controlreadstatus' => false,
-                            'canreplyprivately' => false,
+                            'canreplyprivately' => true,
                             'selfenrol' => false
                         ],
                         'urls' => [
@@ -2925,7 +2943,9 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
                             'delete' => (new moodle_url('/mod/forum/post.php', [
                                 'delete' => $discussion2reply1->id
                             ]))->out(false),
-                            'split' => null,
+                            'split' => (new moodle_url('/mod/forum/post.php', [
+                                'prune' => $discussion2reply1->id
+                            ]))->out(false),
                             'reply' => (new moodle_url('/mod/forum/post.php#mformforum', [
                                 'reply' => $discussion2reply1->id
                             ]))->out(false),
@@ -2966,13 +2986,13 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
                         'charcount' => null,
                         'capabilities' => [
                             'view' => true,
-                            'edit' => false,
-                            'delete' => false,
+                            'edit' => true,
+                            'delete' => true,
                             'split' => false,
                             'reply' => true,
                             'export' => false,
                             'controlreadstatus' => false,
-                            'canreplyprivately' => false,
+                            'canreplyprivately' => true,
                             'selfenrol' => false
                         ],
                         'urls' => [
@@ -2980,8 +3000,12 @@ class mod_forum_external_testcase extends externallib_advanced_testcase {
                                 $discussion2firstpostobject->discussion, $discussion2firstpostobject->id)->out(false),
                             'viewisolated' => $isolatedurlparent->out(false),
                             'viewparent' => null,
-                            'edit' => null,
-                            'delete' => null,
+                            'edit' => (new moodle_url('/mod/forum/post.php', [
+                                'edit' => $discussion2firstpostobject->id
+                            ]))->out(false),
+                            'delete' => (new moodle_url('/mod/forum/post.php', [
+                                'delete' => $discussion2firstpostobject->id
+                            ]))->out(false),
                             'split' => null,
                             'reply' => (new moodle_url('/mod/forum/post.php#mformforum', [
                                 'reply' => $discussion2firstpostobject->id
diff --git a/mod/forum/upgrade.txt b/mod/forum/upgrade.txt
index dc259c0fbfd..154c1f14d91 100644
--- a/mod/forum/upgrade.txt
+++ b/mod/forum/upgrade.txt
@@ -1,6 +1,12 @@
 This files describes API changes in /mod/forum/*,
 information provided here is intended especially for developers.
 
+=== 3.10 ===
+
+* Changes in external function mod_forum_external::get_discussion_posts_by_userid
+  Now returns the posts of a given user checking the current user capabilities ($USER, the user who is requesting the posts).
+  Previously, it returned the posts checking the capabilities of the user that created the posts.
+
 === 3.8 ===
 
 * The following functions have been finally deprecated and can not be used anymore: