Be more tolerant and also accept <esi:include ...></esi:include>, also if it is not 100% standards compliant.

Author: mpdude

HttpCache/Esi.php

@@ -154,8 +154,8 @@ public function process(Request $request, Response $response)
 
  // we don't use a proper XML parser here as we can have ESI tags in a plain text response
  $content = $response->getContent();
- $content = preg_replace_callback('#<esi\:include\s+(.*?)\s*/>#', array($this, 'handleEsiIncludeTag'), $content);
- $content = preg_replace('#<esi\:comment[^>]*/>#', '', $content);
+ $content = preg_replace_callback('#<esi\:include\s+(.*?)\s*(?:/|</esi\:include)>#', array($this, 'handleEsiIncludeTag'), $content);
+ $content = preg_replace('#<esi\:comment[^>]*(?:/|</esi\:comment)>#', '', $content);
  $content = preg_replace('#<esi\:remove>.*?</esi\:remove>#', '', $content);
 
  $response->setContent($content);