From 11d556e42b53d572813600584fcb26a4df083bae Mon Sep 17 00:00:00 2001
From: Pascal Birchler <swissspidy@git.wordpress.org>
Date: Fri, 17 Mar 2017 16:53:08 +0000
Subject: [PATCH] List Tables: Hide 'Empty Trash' and 'Empty Spam' buttons when
 view is already empty.

Props ivantedja, Presskopp, printsachen1, Jaydeep Rami, mathieuhays, cazm.
Fixes #38341.

git-svn-id: https://develop.svn.wordpress.org/trunk@40297 602fd350-edb4-49c9-b593-d223f7449a82
---
 .../includes/class-wp-comments-list-table.php |  2 +-
 .../includes/class-wp-media-list-table.php    |  2 +-
 .../includes/class-wp-posts-list-table.php    |  2 +-
 src/wp-admin/js/edit-comments.js              |  7 +++++
 .../phpunit/tests/admin/includesListTable.php | 27 +++++++++++++++++++
 5 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/src/wp-admin/includes/class-wp-comments-list-table.php b/src/wp-admin/includes/class-wp-comments-list-table.php
index 8f53ae4be7..fa41a7203c 100644
--- a/src/wp-admin/includes/class-wp-comments-list-table.php
+++ b/src/wp-admin/includes/class-wp-comments-list-table.php
@@ -354,7 +354,7 @@ class WP_Comments_List_Table extends WP_List_Table {
 			submit_button( __( 'Filter' ), '', 'filter_action', false, array( 'id' => 'post-query-submit' ) );
 		}
 
-		if ( ( 'spam' === $comment_status || 'trash' === $comment_status ) && current_user_can( 'moderate_comments' ) ) {
+		if ( ( 'spam' === $comment_status || 'trash' === $comment_status ) && current_user_can( 'moderate_comments' ) && $this->has_items() ) {
 			wp_nonce_field( 'bulk-destroy', '_destroy_nonce' );
 			$title = ( 'spam' === $comment_status ) ? esc_attr__( 'Empty Spam' ) : esc_attr__( 'Empty Trash' );
 			submit_button( $title, 'apply', 'delete_all', false );
diff --git a/src/wp-admin/includes/class-wp-media-list-table.php b/src/wp-admin/includes/class-wp-media-list-table.php
index 97b166e59c..805f4017d3 100644
--- a/src/wp-admin/includes/class-wp-media-list-table.php
+++ b/src/wp-admin/includes/class-wp-media-list-table.php
@@ -177,7 +177,7 @@ class WP_Media_List_Table extends WP_List_Table {
 			submit_button( __( 'Filter' ), '', 'filter_action', false, array( 'id' => 'post-query-submit' ) );
 		}
 
-		if ( $this->is_trash && current_user_can( 'edit_others_posts' ) ) {
+		if ( $this->is_trash && current_user_can( 'edit_others_posts' ) && $this->has_items() ) {
 			submit_button( __( 'Empty Trash' ), 'apply', 'delete_all', false );
 		} ?>
 		</div>
diff --git a/src/wp-admin/includes/class-wp-posts-list-table.php b/src/wp-admin/includes/class-wp-posts-list-table.php
index 668c3d20a4..535a2dd0c8 100644
--- a/src/wp-admin/includes/class-wp-posts-list-table.php
+++ b/src/wp-admin/includes/class-wp-posts-list-table.php
@@ -489,7 +489,7 @@ class WP_Posts_List_Table extends WP_List_Table {
 			}
 		}
 
-		if ( $this->is_trash && current_user_can( get_post_type_object( $this->screen->post_type )->cap->edit_others_posts ) ) {
+		if ( $this->is_trash && current_user_can( get_post_type_object( $this->screen->post_type )->cap->edit_others_posts ) && $this->has_items() ) {
 			submit_button( __( 'Empty Trash' ), 'apply', 'delete_all', false );
 		}
 ?>
diff --git a/src/wp-admin/js/edit-comments.js b/src/wp-admin/js/edit-comments.js
index 3de031022c..9e0fc09602 100644
--- a/src/wp-admin/js/edit-comments.js
+++ b/src/wp-admin/js/edit-comments.js
@@ -461,6 +461,13 @@ setCommentsList = function() {
 			updateCountText( 'span.trash-count', trashDiff );
 		}
 
+		if (
+			( ( 'trash' === settings.data.comment_status ) && !getCount( $( 'span.trash-count' ) ) ) ||
+			( ( 'spam' === settings.data.comment_status ) && !getCount( $( 'span.spam-count' ) ) )
+		) {
+			$( '#delete_all' ).hide();
+		}
+
 		if ( ! isDashboard ) {
 			total = totalInput.val() ? parseInt( totalInput.val(), 10 ) : 0;
 			if ( $(settings.target).parent().is('span.undo') )
diff --git a/tests/phpunit/tests/admin/includesListTable.php b/tests/phpunit/tests/admin/includesListTable.php
index b0be74f28c..cf40457cdf 100644
--- a/tests/phpunit/tests/admin/includesListTable.php
+++ b/tests/phpunit/tests/admin/includesListTable.php
@@ -235,4 +235,31 @@ class Tests_Admin_includesListTable extends WP_UnitTestCase {
 
 		$this->assertNotContains( 'id="cat"', $output );
 	}
+
+	/**
+	 * @ticket 38341
+	 */
+	public function test_empty_trash_button_should_not_be_shown_if_there_are_no_posts() {
+		// Set post type to a non-existent one.
+		$this->table->screen->post_type = 'foo';
+
+		ob_start();
+		$this->table->extra_tablenav( 'top' );
+		$output = ob_get_clean();
+
+		$this->assertNotContains( 'id="delete_all"', $output );
+	}
+
+	/**
+	 * @ticket 38341
+	 */
+	public function test_empty_trash_button_should_not_be_shown_if_there_are_no_comments() {
+		$table = _get_list_table( 'WP_Comments_List_Table', array( 'screen' => 'edit-comments' ) );
+
+		ob_start();
+		$table->extra_tablenav( 'top' );
+		$output = ob_get_clean();
+
+		$this->assertNotContains( 'id="delete_all"', $output );
+	}
 }