From e6f8b8c6e0ab6889881fb208bbff4d47676ce528 Mon Sep 17 00:00:00 2001 From: Hypolite Petovan Date: Fri, 2 Dec 2022 08:10:16 -0500 Subject: [PATCH] Ward against preg_replace_callback null return value in Strings::performWithEscapedBlocks - Add logging to troubleshoot potential issue with regex - Address part of https://github.com/friendica/friendica/issues/12011#issuecomment-1335124938 --- src/Util/Strings.php | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/src/Util/Strings.php b/src/Util/Strings.php index 0d7bf66911..379f2a2521 100644 --- a/src/Util/Strings.php +++ b/src/Util/Strings.php @@ -23,6 +23,7 @@ namespace Friendica\Util; use Friendica\Content\ContactSelector; use Friendica\Core\Logger; +use Friendica\Core\System; use ParagonIE\ConstantTime\Base64; /** @@ -480,7 +481,7 @@ class Strings $blocks = []; - $text = preg_replace_callback($regex, + $return = preg_replace_callback($regex, function ($matches) use ($executionId, &$blocks) { $return = '«block-' . $executionId . '-' . count($blocks) . '»'; @@ -491,7 +492,11 @@ class Strings $text ); - $text = $callback($text) ?? ''; + if (is_null($return)) { + Logger::warning('Received null value from preg_replace_callback', ['text' => $text, 'regex' => $regex, 'blocks' => $blocks, 'executionId' => $executionId, 'callstack' => System::callstack(10)]); + } + + $text = $callback($return ?? $text) ?? ''; // Restore code blocks $text = preg_replace_callback('/«block-' . $executionId . '-([0-9]+)»/iU',