From 59c2243cc3928503afe29a890506fb6b6782ae2f Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@users.mediawiki.org>
Date: Wed, 26 Nov 2008 02:28:15 +0000
Subject: [PATCH] Follow-up to r43964 (bug 16440) * Purge newly rendered math
 images from squids, so any old bad versions get purged out * Don't save
 entries that were 0-byte files

---
 includes/Math.php | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/includes/Math.php b/includes/Math.php
index 090400e18b..0bc24bc9c0 100644
--- a/includes/Math.php
+++ b/includes/Math.php
@@ -145,6 +145,10 @@ class MathRenderer {
 				return $this->_error( 'math_image_error' );
 			}
 
+			if( filesize( "$wgTmpDirectory/{$this->hash}.png" ) == 0 ) {
+				return $this->_error( 'math_image_error' );
+			}
+
 			$hashpath = $this->_getHashPath();
 			if( !file_exists( $hashpath ) ) {
 				if( !@wfMkdirParents( $hashpath, 0755 ) ) {
@@ -175,7 +179,14 @@ class MathRenderer {
 				  ), $fname
 				);
 			}
-
+			
+			// If we're replacing an older version of the image, make sure it's current.
+			global $wgUseSquid;
+			if ( $wgUseSquid ) {
+				$urls = array( $this->_mathImageUrl() );
+				$u = new SquidUpdate( $urls );
+				$u->doUpdate();
+			}
 		}
 
 		return $this->_doRender();
@@ -274,10 +285,7 @@ class MathRenderer {
 	}
 
 	function _linkToMathImage() {
-		global $wgMathPath;
-		$url = "$wgMathPath/" . substr($this->hash, 0, 1)
-					.'/'. substr($this->hash, 1, 1) .'/'. substr($this->hash, 2, 1)
-					. "/{$this->hash}.png";
+		$url = $this->_mathImageUrl();
 
 		return Xml::element( 'img',
 			$this->_attribs(
@@ -289,14 +297,24 @@ class MathRenderer {
 					'src' => $url ) ) );
 	}
 
+	function _mathImageUrl() {
+		global $wgMathPath;
+		$dir = $this->_getHashSubPath();
+		return "$wgMathPath/$dir/$this->hash";
+	}
+	
 	function _getHashPath() {
 		global $wgMathDirectory;
-		$path = $wgMathDirectory .'/'. substr($this->hash, 0, 1)
-					.'/'. substr($this->hash, 1, 1)
-					.'/'. substr($this->hash, 2, 1);
+		$path = $wgMathDirectory .'/' . $this->_getHashSubPath();
 		wfDebug( "TeX: getHashPath, hash is: $this->hash, path is: $path\n" );
 		return $path;
 	}
+	
+	function _getHashSubPath() {
+		return substr($this->hash, 0, 1)
+					.'/'. substr($this->hash, 1, 1)
+					.'/'. substr($this->hash, 2, 1);
+	}
 
 	public static function renderMath( $tex, $params=array() ) {
 		global $wgUser;
-- 
2.20.1