From 570f261302f5203de0319ad997e6a68a3c5803b3 Mon Sep 17 00:00:00 2001
From: Loz Calver <lozcalver@bigfork.co.uk>
Date: Wed, 15 Oct 2014 11:25:02 +0100
Subject: [PATCH] FIX: Tag-less cache backends error on flush

---
 i18n/i18n.php       | 13 ++++++++++++-
 model/Aggregate.php | 23 +++++++++++++++--------
 view/SSViewer.php   | 15 +++++++++++++--
 3 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/i18n/i18n.php b/i18n/i18n.php
index c6f8e3bac..6f45197a0 100644
--- a/i18n/i18n.php
+++ b/i18n/i18n.php
@@ -101,7 +101,18 @@ class i18n extends Object implements TemplateGlobalProvider, Flushable {
 	 * Triggered early in the request when someone requests a flush.
 	 */
 	public static function flush() {
-		self::get_cache()->clean(Zend_Cache::CLEANING_MODE_MATCHING_TAG, array('Zend_Translate'));
+		$cache = self::get_cache();
+		$backend = $cache->getBackend();
+
+		if(
+			$backend instanceof Zend_Cache_Backend_ExtendedInterface
+			&& ($capabilities = $backend->getCapabilities())
+			&& $capabilities['tags']
+		) {
+			$cache->clean(Zend_Cache::CLEANING_MODE_MATCHING_TAG, $cache->getTags());
+		} else {
+			$cache->clean(Zend_Cache::CLEANING_MODE_ALL);
+		}
 	}
 
 	/**
diff --git a/model/Aggregate.php b/model/Aggregate.php
index 84cc105e2..1e3287471 100644
--- a/model/Aggregate.php
+++ b/model/Aggregate.php
@@ -50,15 +50,22 @@ class Aggregate extends ViewableData {
 	 */
 	public static function flushCache($class=null) {
 		$cache = self::cache();
-		$capabilities = $cache->getBackend()->getCapabilities();
-		if($capabilities['tags'] && (!$class || $class == 'DataObject')) {
-			$cache->clean(Zend_Cache::CLEANING_MODE_MATCHING_TAG, array('aggregate'));
-		} elseif($capabilities['tags']) {
-			$tags = ClassInfo::ancestry($class);
-			foreach($tags as &$tag) {
-				$tag = preg_replace('/[^a-zA-Z0-9_]/', '_', $tag);
+		$backend = $cache->getBackend();
+
+		if(
+			$backend instanceof Zend_Cache_Backend_ExtendedInterface
+			&& ($capabilities = $backend->getCapabilities())
+			&& $capabilities['tags']
+		) {
+			if( ! $class || $class == 'DataObject') {
+				$cache->clean(Zend_Cache::CLEANING_MODE_MATCHING_TAG, array('aggregate'));
+			} else {
+				$tags = ClassInfo::ancestry($class);
+				foreach($tags as &$tag) {
+					$tag = preg_replace('/[^a-zA-Z0-9_]/', '_', $tag);
+				}
+				$cache->clean(Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG, $tags);
 			}
-			$cache->clean(Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG, $tags);
 		} else {
 			$cache->clean(Zend_Cache::CLEANING_MODE_ALL);
 		}
diff --git a/view/SSViewer.php b/view/SSViewer.php
index e13658706..0bfd23c29 100644
--- a/view/SSViewer.php
+++ b/view/SSViewer.php
@@ -948,8 +948,19 @@ class SSViewer implements Flushable {
 	public static function flush_cacheblock_cache($force = false) {
 		if (!self::$cacheblock_cache_flushed || $force) {
 			$cache = SS_Cache::factory('cacheblock');
-			$tags = $cache->getTags();
-			$cache->clean(Zend_Cache::CLEANING_MODE_MATCHING_TAG, $tags);
+			$backend = $cache->getBackend();
+			
+			if(
+				$backend instanceof Zend_Cache_Backend_ExtendedInterface
+				&& ($capabilities = $backend->getCapabilities())
+				&& $capabilities['tags']
+			) {
+				$cache->clean(Zend_Cache::CLEANING_MODE_MATCHING_TAG, $cache->getTags());
+			} else {
+				$cache->clean(Zend_Cache::CLEANING_MODE_ALL);
+			}
+
+			
 			self::$cacheblock_cache_flushed = true;
 		}
 	}