MDL-64821 mod_forum: fix modern view in single discussion forum

mod/forum/view.php

@@ -76,12 +76,24 @@ $cm = \cm_info::create($coursemodule);
 
 require_course_login($course, true, $cm);
 
+$istypesingle = 'single' === $forum->get_type();
+
+if ($mode) {
+    set_user_preference('forum_displaymode', $mode);
+}
+
+$displaymode = get_user_preferences('forum_displaymode', $CFG->forum_displaymode);
+
 $PAGE->set_context($forum->get_context());
 $PAGE->set_title($forum->get_name());
 $PAGE->add_body_class('forumtype-' . $forum->get_type());
 $PAGE->set_heading($course->fullname);
 $PAGE->set_button(forum_search_form($course, $search));
 
+if ($istypesingle && $displaymode == FORUM_MODE_MODERN) {
+    $PAGE->add_body_class('modern-display-mode reset-style');
+}
+
 if (empty($cm->visible) && !has_capability('moodle/course:viewhiddenactivities', $forum->get_context())) {
     redirect(
         $urlfactory->get_course_url_from_forum($forum),
@@ -125,16 +137,10 @@ if (!empty($CFG->enablerssfeeds) && !empty($CFG->forum_enablerssfeeds) && $forum
 echo $OUTPUT->header();
 echo $OUTPUT->heading(format_string($forum->get_name()), 2);
 
-if ('single' !== $forum->get_type() && !empty($forum->get_intro())) {
+if (!$istypesingle && !empty($forum->get_intro())) {
     echo $OUTPUT->box(format_module_intro('forum', $forumrecord, $cm->id), 'generalbox', 'intro');
 }
 
-if ($mode) {
-    set_user_preference('forum_displaymode', $mode);
-}
-
-$displaymode = get_user_preferences('forum_displaymode', $CFG->forum_displaymode);
-
 if ($sortorder) {
     set_user_preference('forum_discussionlistsortorder', $sortorder);
 }

theme/boost/scss/moodle/modules.scss

@@ -188,18 +188,16 @@ $author-image-margin-sm: 8px;
     }
 }
 
-#page-mod-forum-discuss.modern-display-mode {
-    &.path-mod-forum {
-        .discussionsubscription {
-            margin-top: 0;
-            text-align: inherit;
-            margin-bottom: 0;
-        }
+.path-mod-forum.modern-display-mode {
+    .discussionsubscription {
+        margin-top: 0;
+        text-align: inherit;
+        margin-bottom: 0;
+    }
 
-        .preload-subscribe,
-        .preload-unsubscribe {
-            display: none;
-        }
+    .preload-subscribe,
+    .preload-unsubscribe {
+        display: none;
     }
 
     .post-message {

theme/boost/scss/moodle/undo.scss

@@ -217,17 +217,16 @@ $allow-reset-style: true !default;
             padding-bottom: 0 !important;  /* stylelint-disable-line declaration-no-important */
 
             #region-main-box {
-                display: flex;
-
                 #region-main {
                     border: none;
-                    display: flex;
+                    display: inline-flex;
                     flex-direction: column;
                     padding: 0;
                     height: 100%;
                     width: 100%;
                     padding-left: $card-spacer-x;
                     padding-right: $card-spacer-x;
+                    vertical-align: top;
 
                     div[role="main"] {
                         flex: 1;
@@ -251,6 +250,7 @@ $allow-reset-style: true !default;
                 }
 
                 @include media-breakpoint-down(lg) {
+                    display: flex;
                     flex-direction: column;
                 }
             }