Ticket #25408: 25408.22.diff

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

@@ -832 +832 @@
          * @return string Name of the default primary column, in this case, an empty string.
          */
         protected function get_default_primary_column_name() {
-                return '';
+                $columns = $this->get_columns();
+                $column = '';
+
+                // We need a primary defined so responsive views show something,
+                // so let's fall back to the first non-checkbox column.
+                foreach( $columns as $col => $column_name ) {
+                        if ( 'cb' === $col ) {
+                                continue;
+                        }
+
+                        $column = $col;
+                        break;
+                }
+
+                return $column;
         }
 
         /**
@@ -878 +892 @@
                 if ( isset( $this->_column_headers ) && is_array( $this->_column_headers ) ) {
                         // Back-compat for list tables that have been manually setting $_column_headers for horse reasons.
                         // In 4.3, we added a fourth argument for primary column.
-                        $column_headers = array( array(), array(), array(), '' );
+                        $column_headers = array( array(), array(), array(), $this->get_primary_column_name() );
                         foreach ( $this->_column_headers as $key => $value ) {
                                 $column_headers[ $key ] = $value;
                         }