From fe3d23f0d4c381040f47d24c4dcc9b27768a06b8 Mon Sep 17 00:00:00 2001
From: Damian Mooyman <damian@silverstripe.com>
Date: Fri, 23 Oct 2015 11:46:58 +1300
Subject: [PATCH] BUG Fix GeneratedAssetHandler crashing on expired resources

---
 .../storage/CacheGeneratedAssetHandler.php    | 28 ++++++++++++-------
 tests/filesystem/AssetStoreTest.php           | 11 ++++++++
 2 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/filesystem/storage/CacheGeneratedAssetHandler.php b/filesystem/storage/CacheGeneratedAssetHandler.php
index 439cab2a7..2c6c47989 100644
--- a/filesystem/storage/CacheGeneratedAssetHandler.php
+++ b/filesystem/storage/CacheGeneratedAssetHandler.php
@@ -105,7 +105,10 @@ class CacheGeneratedAssetHandler implements GeneratedAssetHandler, Flushable {
 		$data = $cache->load($cacheID);
 		if($data) {
 			$result = unserialize($data);
-			return $this->validateResult($result, $filename);
+			$valid = $this->validateResult($result, $filename);
+			if($valid) {
+				return $result;
+			}
 		}
 
 		// Regenerate
@@ -127,8 +130,14 @@ class CacheGeneratedAssetHandler implements GeneratedAssetHandler, Flushable {
 		if($result) {
 			$cache->save(serialize($result), $cacheID);
 		}
-		
-		return $this->validateResult($result, $filename);
+
+		// Ensure this result is successfully saved
+		$valid = $this->validateResult($result, $filename);
+		if($valid) {
+			return $result;
+		}
+
+		throw new Exception("Error regenerating file \"{$filename}\"");
 	}
 
 	/**
@@ -151,17 +160,16 @@ class CacheGeneratedAssetHandler implements GeneratedAssetHandler, Flushable {
 	 *
 	 * @param mixed $result
 	 * @param string $filename
-	 * @return array The result
-	 * @throws Exception
+	 * @return bool True if this $result is valid
 	 */
 	protected function validateResult($result, $filename) {
+		if(!$result) {
+			return false;
+		}
+		
 		// Retrieve URL from tuple
 		$store = $this->getAssetStore();
-		if($result && $store->exists($result['Filename'], $result['Hash'], $result['Variant'])) {
-			return $result;
-		}
-
-		throw new Exception("Error regenerating file \"{$filename}\"");
+		return $store->exists($result['Filename'], $result['Hash'], $result['Variant']);
 	}
 
 }
diff --git a/tests/filesystem/AssetStoreTest.php b/tests/filesystem/AssetStoreTest.php
index bd4454a84..1d11606cf 100644
--- a/tests/filesystem/AssetStoreTest.php
+++ b/tests/filesystem/AssetStoreTest.php
@@ -7,6 +7,7 @@ use SilverStripe\Filesystem\Flysystem\FlysystemAssetStore;
 use SilverStripe\Filesystem\Flysystem\FlysystemUrlPlugin;
 use SilverStripe\Filesystem\Storage\AssetContainer;
 use SilverStripe\Filesystem\Storage\AssetStore;
+use SilverStripe\Filesystem\Storage\CacheGeneratedAssetHandler;
 
 class AssetStoreTest extends SapphireTest {
 
@@ -450,6 +451,10 @@ class AssetStoreTest_SpyStore extends FlysystemAssetStore {
 	 * Reset defaults for this store
 	 */
 	public static function reset() {
+		// Need flushing since it won't have any files left
+		CacheGeneratedAssetHandler::flush();
+
+		// Remove all files in this store
 		if(self::$basedir) {
 			$path = self::base_path();
 			if(file_exists($path)) {
@@ -469,6 +474,12 @@ class AssetStoreTest_SpyStore extends FlysystemAssetStore {
 		if($asset instanceof Folder) {
 			return self::base_path() . '/' . $asset->getFilename();
 		}
+		if($asset instanceof File) {
+			$asset = $asset->File;
+		}
+		if($asset instanceof DBFile) {
+			return BASE_PATH . $asset->getSourceURL();
+		}
 		return BASE_PATH . $asset->getUrl();
 	}