Ticket #29580: 29580.diff

src/wp-admin/themes.php

@@ -26 +26 @@
                 $theme = wp_get_theme( $_GET['stylesheet'] );
                 if ( !current_user_can('delete_themes') || ! $theme->exists() )
                         wp_die( __( 'Cheatin’ uh?' ) );
-                delete_theme($_GET['stylesheet']);
-                wp_redirect( admin_url('themes.php?deleted=true') );
+                $active = wp_get_theme();
+                if ( $active->get( "Template" ) == $_GET['stylesheet'] ) {
+                        wp_redirect( admin_url( 'themes.php?active-child=true' ) );
+                } else {
+                        delete_theme( $_GET['stylesheet'] );
+                        wp_redirect( admin_url( 'themes.php?deleted=true' ) );
+                }
                 exit;
         }
 }
@@ -133 +138 @@
                 }
         elseif ( isset($_GET['deleted']) ) : ?>
 <div id="message3" class="updated"><p><?php _e('Theme deleted.') ?></p></div>
+<?php elseif ( isset( $_GET['active-child'] ) ) : ?>
+        <div id="message4" class="error"><p><?php _e( 'You cannot delete a theme while it has an active child theme.' ); ?></p></div>
 <?php
 endif;
 

src/wp-admin/includes/theme.php

@@ -407 +407 @@
 
         WP_Theme::sort_by_name( $themes );
         foreach ( $themes as $theme ) {
+                $slug = $theme->get_stylesheet();
+                $encoded_slug = urlencode( $slug );
+
                 $parent = false;
                 if ( $theme->parent() ) {
                         $parent = $theme->parent()->display( 'Name' );
+                        $parents[ $slug ] = $theme->parent()->get_stylesheet();
                 }
 
-                $slug = $theme->get_stylesheet();
-                $encoded_slug = urlencode( $slug );
-
                 $prepared_themes[ $slug ] = array(
                         'id'           => $slug,
                         'name'         => $theme->display( 'Name' ),
@@ -443 +444 @@
                 );
         }
 
+        // Remove 'delete' action if theme has an active child
+        if ( isset( $parents ) && array_key_exists( $current_theme, $parents ) ) {
+                unset( $prepared_themes[ $parents[ $current_theme ] ]['actions']['delete'] );
+        }
+
         /**
          * Filter the themes prepared for JavaScript, for themes.php.
          *