WordPress 3.5.1
[autoinstalls/wordpress.git] / wp-includes / class-wp.php
index b1b1e2876e301b26441d011eb0731f4f42bd5347..c76030b32c35fa9112f42e5f683d7c319c82150a 100644 (file)
@@ -378,12 +378,29 @@ class WP {
 
                if ( ! empty( $status ) )
                        status_header( $status );
+
+               // If Last-Modified is set to false, it should not be sent (no-cache situation).
+               if ( isset( $headers['Last-Modified'] ) && false === $headers['Last-Modified'] ) {
+                       unset( $headers['Last-Modified'] );
+
+                       // In PHP 5.3+, make sure we are not sending a Last-Modified header.
+                       if ( function_exists( 'header_remove' ) ) {
+                               @header_remove( 'Last-Modified' );
+                       } else {
+                               // In PHP 5.2, send an empty Last-Modified header, but only as a
+                               // last resort to override a header already sent. #WP23021
+                               foreach ( headers_list() as $header ) {
+                                       if ( 0 === stripos( $header, 'Last-Modified' ) ) {
+                                               $headers['Last-Modified'] = '';
+                                               break;
+                                       }
+                               }
+                       }
+               }
+
                foreach( (array) $headers as $name => $field_value )
                        @header("{$name}: {$field_value}");
 
-               if ( isset( $headers['Last-Modified'] ) && empty( $headers['Last-Modified'] ) && function_exists( 'header_remove' ) )
-                       @header_remove( 'Last-Modified' );
-
                if ( $exit_required )
                        exit();