Some cleanup to header output; use a forced expires header again to force some older...

diff --git a/includes/OutputPage.php b/includes/OutputPage.php
index 03c50c9..4a5376a 100644 (file)
--- a/includes/OutputPage.php
+++ b/includes/OutputPage.php
@@ -248,18 +248,27 @@ class OutputPage {
        }
 
        function sendCacheControl() {
+               global $wgUseSquid;
+               # FIXME: This header may cause trouble with some versions of Internet Explorer
                header( "Vary: Accept-Encoding, Cookie" );
                if( $this->mLastModified != "" ) {
-                        wfDebug( "** private caching; {$this->mLastModified} **\n", false );
-                        if (isset($_COOKIE[ini_get("session.name")] )){
-                                header( "Cache-Control: no-cache, must-revalidate, max-age=0" );
-                        } else {
-                                header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
-                        }
+                       if( $wgUseSquid && ! isset( $_COOKIE[ini_get( "session.name") ] ) ) {
+                               # We'll purge the proxy cache for anons explicitly, but require end user agents
+                               # to revalidate against the proxy on each visit.
+                               wfDebug( "** local proxy caching; {$this->mLastModified} **\n", false );
+                               header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
+                       } else {
+                               # We do want clients to cache if they can, but they *must* check for updates
+                               # on revisiting the page.
+                               wfDebug( "** private caching; {$this->mLastModified} **\n", false );
+                               header( "Expires: -1" );
+                               header( "Cache-Control: private, must-revalidate, max-age=0" );
+                       }
                        header( "Last-modified: {$this->mLastModified}" );
                } else {
                        wfDebug( "** no caching **\n", false );
-                       header( "Cache-Control: no-cache" ); # Experimental - see below
+                       header( "Expires: -1" );
+                       header( "Cache-Control: no-cache" );
                        header( "Pragma: no-cache" );
                        header( "Last-modified: " . gmdate( "D, j M Y H:i:s" ) . " GMT" );
                }