Ticket #37826: 37826.3.patch

src/wp-admin/comment.php

@@ -33 +33 @@
                 $action = 'trash';
 }
 
+/** Stop operation if the post associated with the comment is trashed. */
+$comment_id = absint( $_GET['c'] );
+$comment = get_comment( $comment_id );
+if ( 'trash' === get_post_status( $comment->comment_post_ID ) )
+        wp_die( __( 'You can’t operate on this comment because the associated post is in the Trash. Please restore the post first, then try again.' ) );
+
 switch( $action ) {
 
 case 'editcomment' :

src/wp-admin/includes/class-wp-list-table.php

@@ -659 +659 @@
                         printf( '<span aria-hidden="true">—</span><span class="screen-reader-text">%s</span>',
                                 __( 'No comments' )
                         );
+                // Approved comments AND Posts that were trashed. Hyperlinks for editing are removed.
+                } elseif ( $approved_comments && 'trash' === get_post_status( $post_id ) ) {
+                        printf( '<span class="post-com-count post-com-count-approved"><span class="comment-count-approved" aria-hidden="true">%s</span><span class="screen-reader-text">%s</span></span>',
+                                $approved_comments_number,
+                                $pending_comments ? $approved_phrase : $approved_only_phrase
+                        );
                 // Approved comments have different display depending on some conditions.
                 } elseif ( $approved_comments ) {
                         printf( '<a href="%s" class="post-com-count post-com-count-approved"><span class="comment-count-approved" aria-hidden="true">%s</span><span class="screen-reader-text">%s</span></a>',