[BUGFIX] Prevent PHP segfault when content gets too long

The regular expression for detecting the TYPO3SEARCH_begin /
TYPO3SEARCH_end markers is modified to prevent PHP segfaults
when the content of the page gets too long, see:

https://bugs.php.net/bug.php?id=45735

Resolves: #66346
Change-Id: Ic3f73098ce4f8c56e4101fefba6ca7e839176d95

Author: astehlik

Classes/Typo3PageContentExtractor.php

@@ -69,9 +69,9 @@ public function getIndexableContent() {
 	 * @return	string	HTML markup found between TYPO3SEARCH markers
 	 */
 	protected function extractContentMarkedForIndexing($html) {
-		preg_match_all('/\<\!\-\-[\s]?TYPO3SEARCH_begin[\s]?\-\-\>(.|\s)*?\<\!\-\-[\s]?TYPO3SEARCH_end[\s]?\-\-\>/mi', $html, $indexableContents);
+		preg_match_all('/<!--\s*?TYPO3SEARCH_begin\s*?-->.*?<!--\s*?TYPO3SEARCH_end\s*?-->/mis', $html, $indexableContents);
 		$indexableContent = implode($indexableContents[0], '');
-		
+
 		if(empty($indexableContent) && $GLOBALS['TSFE']->tmpl->setup['plugin.']['tx_solr.']['logging.']['indexing.']['missingTypo3SearchMarkers']) {
 			t3lib_div::devLog('No TYPO3SEARCH markers found.', 'solr', 2);
 		}