[BUGFIX] Fix #160: disable cHash recalculation by default

Classes/Configuration/ConfigurationReader.php

@@ -87,6 +87,7 @@ class ConfigurationReader {
 		'fileName/defaultToHTMLsuffixOnPrev' => FALSE,
 		'init/appendMissingSlash' => 'ifNotFile,redirect[301]',
 		'init/emptySegmentValue' => '',
+		'init/recalculateChashIfMissing' => false,
 		'pagePath/spaceCharacter' => '-', // undocumented & deprecated!
 	);
 

Classes/Decoder/UrlDecoder.php

@@ -33,19 +33,21 @@
 use DmitryDulepov\Realurl\Cache\UrlCacheEntry;
 use DmitryDulepov\Realurl\Configuration\ConfigurationReader;
 use DmitryDulepov\Realurl\EncodeDecoderBase;
+use TYPO3\CMS\Core\SingletonInterface;
 use TYPO3\CMS\Core\Utility\ArrayUtility;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Core\Utility\MathUtility;
 use TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController;
 use TYPO3\CMS\Frontend\Page\PageRepository;
 
 /**
- * This class contains URL decoder for the RealURL.
+ * This class contains URL decoder for the RealURL. It is singleton because the
+ * same instance must run in two different hooks.
  *
  * @package DmitryDulepov\Realurl\Decoder
  * @author Dmitry Dulepov <[email protected]>
  */
-class UrlDecoder extends EncodeDecoderBase {
+class UrlDecoder extends EncodeDecoderBase implements SingletonInterface {
 
 	const REDIRECT_STATUS_HEADER = 'HTTP/1.0 301 TYPO3 RealURL Redirect';
 	const REDIRECT_INFO_HEADER = 'X-TYPO3-RealURL-Info';
@@ -56,6 +58,9 @@ class UrlDecoder extends EncodeDecoderBase {
 	/** @var TypoScriptFrontendController */
 	protected $caller;
 
+	/** @var UrlCacheEntry */
+	protected $createdCacheEntry = null;
+
 	/** @var int */
 	protected $detectedLanguageId = 0;
 
@@ -145,6 +150,35 @@ public function decodeUrl(array $params) {
 		}
 	}
 
+	/**
+	 * Stores decoded record to the URL cache. This function is called after
+	 * TSFE validates cHash. This way we avoid storing URLs with wrong cHash
+	 * in the cache that would always lead to a 404 until URL cache is cleared.
+	 *
+	 * Currently this function uses 'configArrayPostProc' because this hook
+	 * is closest to the TypoScriptFrontendController::makeCacheHash(). If
+	 * execution comes here, than cHash is validated (assuming that
+	 * $TYPO3_CONF_VARS['FE']['pageNotFoundOnCHashError'] is true). However
+	 * it may not be the best place. Another place could be
+	 * TypoScriptFrontendController::hook_eofe(), which runs after the content
+	 * is generated. Advantage is that the URL to the current page could be
+	 * already generated by the encoding process, which is guaranteed to make
+	 * the URL correctly. On the other hand, if content generation fails for
+	 * some reason, we will not have entries in any case and the next call
+	 * to this URL will have to make costly decoding again. To avoid the
+	 * problem, we do it in the earlier hook. Later, when expiration of URL
+	 * entries is implemented, we could set expiration time for this record
+	 * and the encoder will unexpire it if it generates the same URL. The
+	 * advantage of this is that there will be a proper redirect and no
+	 * duplicate content due to possibly different encoded URL.
+	 */
+	public function storeCacheRecord() {
+		// If it is still not there (could have been added by other process!), than store it
+		if ($this->createdCacheEntry && !$this->isExpiredPath && !$this->getFromUrlCache($this->speakingUri)) {
+			$this->putToUrlCache($this->createdCacheEntry);
+		}
+	}
+
 	/**
 	 * Calculates and adds cHash to the entry. This function is only called
 	 * if we had to decode the entry, which was not in the cache. Even if we
@@ -157,13 +191,15 @@ public function decodeUrl(array $params) {
 	 */
 	protected function calculateChash(UrlCacheEntry $cacheEntry) {
 		$requestVariables = $cacheEntry->getRequestVariables();
-		$cacheHashCalculator = GeneralUtility::makeInstance('TYPO3\\CMS\\Frontend\\Page\\CacheHashCalculator');
-		/* @var \TYPO3\CMS\Frontend\Page\CacheHashCalculator $cacheHashCalculator */
-		$cHashParameters = $cacheHashCalculator->getRelevantParameters(GeneralUtility::implodeArrayForUrl('', $requestVariables));
+		if (!isset($requestVariables['cHash']) && $this->configuration->get('init/recalculateChashIfMissing')) {
+			$cacheHashCalculator = GeneralUtility::makeInstance('TYPO3\\CMS\\Frontend\\Page\\CacheHashCalculator');
+			/* @var \TYPO3\CMS\Frontend\Page\CacheHashCalculator $cacheHashCalculator */
+			$cHashParameters = $cacheHashCalculator->getRelevantParameters(GeneralUtility::implodeArrayForUrl('', $requestVariables));
 
-		if (count($cHashParameters) > 0) {
-			$requestVariables['cHash'] = $cacheHashCalculator->calculateCacheHash($cHashParameters);
-			$cacheEntry->setRequestVariables($requestVariables);
+			if (count($cHashParameters) > 0) {
+				$requestVariables['cHash'] = $cacheHashCalculator->calculateCacheHash($cHashParameters);
+				$cacheEntry->setRequestVariables($requestVariables);
+			}
 		}
 	}
 
@@ -1263,10 +1299,7 @@ protected function runDecoding() {
 		$this->checkExpiration($cacheEntry);
 		$this->setRequestVariables($cacheEntry);
 
-		// If it is still not there (could have been added by other process!), than update
-		if (!$this->isExpiredPath && !$this->getFromUrlCache($this->speakingUri)) {
-			$this->putToUrlCache($cacheEntry);
-		}
+		$this->createdCacheEntry = $cacheEntry;
 	}
 
 	/**

ext_localconf.php

@@ -38,6 +38,7 @@ function includeRealurlConfiguration() {
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tstemplate.php']['linkData-PostProc']['realurl'] = 'DmitryDulepov\\Realurl\\Encoder\\UrlEncoder->encodeUrl';
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['tslib/class.tslib_content.php']['typoLink_PostProc']['realurl'] = 'DmitryDulepov\\Realurl\\Encoder\\UrlEncoder->postProcessEncodedUrl';
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['tslib/class.tslib_fe.php']['checkAlternativeIdMethods-PostProc']['realurl'] = 'DmitryDulepov\\Realurl\\Decoder\\UrlDecoder->decodeUrl';
+$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['tslib/class.tslib_fe.php']['configArrayPostProc']['realurl'] = 'DmitryDulepov\\Realurl\\Decoder\\UrlDecoder->storeCacheRecord';
 
 includeRealurlConfiguration();