Merge pull request #8729 from MrPetovan/bug/8726-mention-parsing

Add tag escaping to BBCode::setTags

doc/BBCode.md

@@ -613,15 +613,26 @@ On Mastodon this field is used for the content warning.
   <th>Result</th>
 </tr>
 <tr>
-  <td>If you need to put literal bbcode in a message, [noparse], [nobb] or [pre] are used to escape bbcode:
+  <td>If you need to put literal BBCode in a message, [noparse], [nobb] or [pre] blocks prevent BBCode conversion:
     <ul>
       <li>[noparse][b]bold[/b][/noparse]</li>
       <li>[nobb][b]bold[/b][/nobb]</li>
       <li>[pre][b]bold[/b][/pre]</li>
     </ul>
+    Note: [code] has priority over [noparse], [nobb] and [pre] which makes them display as BBCode tags in code blocks instead of being removed.
+    [code] blocks inside [noparse] will still be converted to a code block.
   </td>
   <td>[b]bold[/b]</td>
 </tr>
+<tr>
+  <td>Additionally, [noparse] and [pre] blocks prevent mention and hashtag conversion to links:
+    <ul>
+      <li>[noparse]@user@domain.tld #hashtag[/noparse]</li>
+      <li>[pre]@user@domain.tld #hashtag[/pre]</li>
+    </ul>
+  </td>
+  <td>@user@domain.tld #hashtag</td>
+</tr>
 <tr>
   <td>[nosmile] is used to disable smilies on a post by post basis<br>
     <br>

include/api.php

@@ -624,7 +624,7 @@ function api_get_user(App $a, $contact_id = null)
 				'name' => $contact["name"],
 				'screen_name' => (($contact['nick']) ? $contact['nick'] : $contact['name']),
 				'location' => ($contact["location"] != "") ? $contact["location"] : ContactSelector::networkToName($contact['network'], $contact['url'], $contact['protocol']),
-				'description' => BBCode::toPlaintext($contact["about"]),
+				'description' => BBCode::toPlaintext($contact["about"] ?? ''),
 				'profile_image_url' => $contact["micro"],
 				'profile_image_url_https' => $contact["micro"],
 				'profile_image_url_profile_size' => $contact["thumb"],
@@ -698,7 +698,7 @@ function api_get_user(App $a, $contact_id = null)
 		'name' => (($uinfo[0]['name']) ? $uinfo[0]['name'] : $uinfo[0]['nick']),
 		'screen_name' => (($uinfo[0]['nick']) ? $uinfo[0]['nick'] : $uinfo[0]['name']),
 		'location' => $location,
-		'description' => BBCode::toPlaintext($description),
+		'description' => BBCode::toPlaintext($description ?? ''),
 		'profile_image_url' => $uinfo[0]['micro'],
 		'profile_image_url_https' => $uinfo[0]['micro'],
 		'profile_image_url_profile_size' => $uinfo[0]["thumb"],

include/enotify.php

@@ -465,7 +465,7 @@ function notification($params)
 	if ($show_in_notification_page) {
 		$notification = DI::notify()->insert([
 			'name'          => $params['source_name'] ?? '',
-			'name_cache'    => substr(strip_tags(BBCode::convert($params['source_name'] ?? '')), 0, 255),
+			'name_cache'    => substr(strip_tags(BBCode::convert($params['source_name'])), 0, 255),
 			'url'           => $params['source_link'] ?? '',
 			'photo'         => $params['source_photo'] ?? '',
 			'link'          => $itemlink ?? '',

mod/cal.php

@@ -78,7 +78,7 @@ function cal_init(App $a)
 		'$photo' => $profile['photo'],
 		'$addr' => $profile['addr'] ?: '',
 		'$account_type' => $account_type,
-		'$about' => BBCode::convert($profile['about'] ?: ''),
+		'$about' => BBCode::convert($profile['about']),
 	]);
 
 	$cal_widget = Widget\CalendarExport::getHTML();

mod/item.php

@@ -369,16 +369,16 @@ function item_post(App $a) {
 
 	// Look for any tags and linkify them
 	$inform   = '';
+	$private_forum = false;
+	$private_id = null;
+	$only_to_forum = false;
+	$forum_contact = [];
 
+	BBCode::performWithEscapedTags($body, ['noparse', 'pre', 'code'], function ($body) use ($profile_uid, $network, $str_contact_allow, &$inform, &$private_forum, &$private_id, &$only_to_forum, &$forum_contact) {
 		$tags = BBCode::getTags($body);
 
 		$tagged = [];
 
-	$private_forum = false;
-	$only_to_forum = false;
-	$forum_contact = [];
-
-	if (count($tags)) {
 		foreach ($tags as $tag) {
 			$tag_type = substr($tag, 0, 1);
 
@@ -386,41 +386,36 @@ function item_post(App $a) {
 				continue;
 			}
 
-			/*
+			/* If we already tagged 'Robert Johnson', don't try and tag 'Robert'.
-			 * If we already tagged 'Robert Johnson', don't try and tag 'Robert'.
 			 * Robert Johnson should be first in the $tags array
 			 */
-			$fullnametagged = false;
-			/// @TODO $tagged is initialized above if () block and is not filled, maybe old-lost code?
 			foreach ($tagged as $nextTag) {
 				if (stristr($nextTag, $tag . ' ')) {
-					$fullnametagged = true;
+					continue 2;
-					break;
 				}
 			}
-			if ($fullnametagged) {
-				continue;
-			}
 
 			$success = handle_tag($body, $inform, local_user() ? local_user() : $profile_uid, $tag, $network);
 			if ($success['replaced']) {
 				$tagged[] = $tag;
 			}
 			// When the forum is private or the forum is addressed with a "!" make the post private
-			if (is_array($success['contact']) && (!empty($success['contact']['prv']) || ($tag_type == Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION]))) {
+			if (!empty($success['contact']['prv']) || ($tag_type == Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION])) {
 				$private_forum = $success['contact']['prv'];
 				$only_to_forum = ($tag_type == Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION]);
 				$private_id = $success['contact']['id'];
 				$forum_contact = $success['contact'];
-			} elseif (is_array($success['contact']) && !empty($success['contact']['forum']) &&
+			} elseif (!empty($success['contact']['forum']) && ($str_contact_allow == '<' . $success['contact']['id'] . '>')) {
-				($str_contact_allow == '<' . $success['contact']['id'] . '>')) {
 				$private_forum = false;
 				$only_to_forum = true;
 				$private_id = $success['contact']['id'];
 				$forum_contact = $success['contact'];
 			}
 		}
-	}
+
+		return $body;
+	});
+
 
 	$original_contact_id = $contact_id;
 
@@ -642,7 +637,7 @@ function item_post(App $a) {
 
 	// Check for hashtags in the body and repair or add hashtag links
 	if ($preview || $orig_post) {
-		Item::setHashtags($datarray);
+		$datarray['body'] = Item::setHashtags($datarray['body']);
 	}
 
 	// preview mode - prepare the body for display and send it via json

mod/photos.php

@@ -82,7 +82,7 @@ function photos_init(App $a) {
 			'$photo' => $profile['photo'],
 			'$addr' => $profile['addr'] ?? '',
 			'$account_type' => $account_type,
-			'$about' => BBCode::convert($profile['about'] ?? ''),
+			'$about' => BBCode::convert($profile['about']),
 		]);
 
 		$albums = Photo::getAlbums($a->data['user']['uid']);

mod/poco.php

@@ -204,7 +204,10 @@ function poco_init(App $a) {
 		}
 	}
 
-	if (is_array($contacts)) {
+	if (!is_array($contacts)) {
+		throw new \Friendica\Network\HTTPException\InternalServerErrorException();
+	}
+
 	if (DBA::isResult($contacts)) {
 		foreach ($contacts as $contact) {
 			if (!isset($contact['updated'])) {
@@ -338,9 +341,6 @@ function poco_init(App $a) {
 	} else {
 		$ret['entry'][] = [];
 	}
-	} else {
-		throw new \Friendica\Network\HTTPException\InternalServerErrorException();
-	}
 
 	Logger::log("End of poco", Logger::DEBUG);
 

mod/videos.php

@@ -67,7 +67,7 @@ function videos_init(App $a)
 			'$photo' => $profile['photo'],
 			'$addr' => $profile['addr'] ?? '',
 			'$account_type' => $account_type,
-			'$about' => BBCode::convert($profile['about'] ?? ''),
+			'$about' => BBCode::convert($profile['about']),
 		]);
 
 		// If not there, create 'aside' empty

src/Content/Text/BBCode.php

@@ -1252,10 +1252,17 @@ class BBCode
 	 * @return string
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function convert($text, $try_oembed = true, $simple_html = self::INTERNAL, $for_plaintext = false)
+	public static function convert(string $text = null, $try_oembed = true, $simple_html = self::INTERNAL, $for_plaintext = false)
 	{
+		// Accounting for null default column values
+		if (is_null($text) || $text === '') {
+			return '';
+		}
+
 		$a = DI::app();
 
+		$text = self::performWithEscapedTags($text, ['code'], function ($text) use ($try_oembed, $simple_html, $for_plaintext, $a) {
+			$text = self::performWithEscapedTags($text, ['noparse', 'nobb', 'pre'], function ($text) use ($try_oembed, $simple_html, $for_plaintext, $a) {
 				/*
 				 * preg_match_callback function to replace potential Oembed tags with Oembed content
 				 *
@@ -1277,29 +1284,7 @@ class BBCode
 					return $return;
 				};
 
-		// Extracting code blocks before the whitespace processing and the autolinker
-		$codeblocks = [];
 
-		$text = preg_replace_callback("#\[code(?:=([^\]]*))?\](.*?)\[\/code\]#ism",
-			function ($matches) use (&$codeblocks) {
-				$return = '#codeblock-' . count($codeblocks) . '#';
-				if (strpos($matches[2], "\n") !== false) {
-					$codeblocks[] = '<pre><code class="language-' . trim($matches[1]) . '">' . htmlspecialchars(trim($matches[2], "\n\r"), ENT_NOQUOTES, 'UTF-8') . '</code></pre>';
-				} else {
-					$codeblocks[] = '<code>' . htmlspecialchars($matches[2], ENT_NOQUOTES, 'UTF-8') . '</code>';
-				}
-
-				return $return;
-			},
-			$text
-		);
-
-		// Hide all [noparse] contained bbtags by spacefying them
-		// POSSIBLE BUG --> Will the 'preg' functions crash if there's an embedded image?
-
-		$text = preg_replace_callback("/\[noparse\](.*?)\[\/noparse\]/ism", 'self::escapeNoparseCallback', $text);
-		$text = preg_replace_callback("/\[nobb\](.*?)\[\/nobb\]/ism", 'self::escapeNoparseCallback', $text);
-		$text = preg_replace_callback("/\[pre\](.*?)\[\/pre\]/ism", 'self::escapeNoparseCallback', $text);
 
 				// Remove the abstract element. It is a non visible element.
 				$text = self::stripAbstract($text);
@@ -1834,13 +1819,6 @@ class BBCode
 				$text = preg_replace("/\[mail\](.*?)\[\/mail\]/", '<a href="mailto:$1">$1</a>', $text);
 				$text = preg_replace("/\[mail\=(.*?)\](.*?)\[\/mail\]/", '<a href="mailto:$1">$2</a>', $text);
 
-		// Unhide all [noparse] contained bbtags unspacefying them
-		// and triming the [noparse] tag.
-
-		$text = preg_replace_callback("/\[noparse\](.*?)\[\/noparse\]/ism", 'self::unescapeNoparseCallback', $text);
-		$text = preg_replace_callback("/\[nobb\](.*?)\[\/nobb\]/ism", 'self::unescapeNoparseCallback', $text);
-		$text = preg_replace_callback("/\[pre\](.*?)\[\/pre\]/ism", 'self::unescapeNoparseCallback', $text);
-
 				/// @todo What is the meaning of these lines?
 				$text = preg_replace('/\[\&amp\;([#a-z0-9]+)\;\]/', '&$1;', $text);
 				$text = preg_replace('/\&\#039\;/', '\'', $text);
@@ -1882,17 +1860,27 @@ class BBCode
 					}
 				);
 
-		if ($saved_image) {
 				$text = self::interpolateSavedImagesIntoItemBody($text, $saved_image);
+
+				return $text;
+			}); // Escaped noparse, nobb, pre
+
+			// Remove escaping tags
+			$text = preg_replace("/\[noparse\](.*?)\[\/noparse\]/ism", '\1', $text);
+			$text = preg_replace("/\[nobb\](.*?)\[\/nobb\]/ism", '\1', $text);
+			$text = preg_replace("/\[pre\](.*?)\[\/pre\]/ism", '\1', $text);
+
+			return $text;
+		}); // Escaped code
+
+		$text = preg_replace_callback("#\[code(?:=([^\]]*))?\](.*?)\[\/code\]#ism",
+			function ($matches) {
+				if (strpos($matches[2], "\n") !== false) {
+					$return = '<pre><code class="language-' . trim($matches[1]) . '">' . htmlspecialchars(trim($matches[2], "\n\r"), ENT_NOQUOTES, 'UTF-8') . '</code></pre>';
+				} else {
+					$return = '<code>' . htmlspecialchars($matches[2], ENT_NOQUOTES, 'UTF-8') . '</code>';
 				}
 
-		// Restore code blocks
-		$text = preg_replace_callback('/#codeblock-([0-9]+)#/iU',
-			function ($matches) use ($codeblocks) {
-				$return = $matches[0];
-				if (isset($codeblocks[intval($matches[1])])) {
-					$return = $codeblocks[$matches[1]];
-				}
 				return $return;
 			},
 			$text
@@ -2104,12 +2092,10 @@ class BBCode
 	{
 		$ret = [];
 
+		BBCode::performWithEscapedTags($string, ['noparse', 'pre', 'code'], function ($string) use (&$ret) {
 			// Convert hashtag links to hashtags
 			$string = preg_replace('/#\[url\=([^\[\]]*)\](.*?)\[\/url\]/ism', '#$2 ', $string);
 
-		// ignore anything in a code block
-		$string = preg_replace('/\[code.*?\].*?\[\/code\]/sm', '', $string);
-
 			// Force line feeds at bbtags
 			$string = str_replace(['[', ']'], ["\n[", "]\n"], $string);
 
@@ -2137,17 +2123,13 @@ class BBCode
 			// Otherwise pull out single word tags. These can be @nickname, @first_last
 			// and #hash tags.
 
-		if (preg_match_all('/([!#@][^\^ \x0D\x0A,;:?]+)([ \x0D\x0A,;:?]|$)/', $string, $matches)) {
+			if (preg_match_all('/([!#@][^\^ \x0D\x0A,;:?\']*[^\^ \x0D\x0A,;:?!\'.])/', $string, $matches)) {
 				foreach ($matches[1] as $match) {
 					if (strstr($match, ']')) {
 						// we might be inside a bbcode color tag - leave it alone
 						continue;
 					}
 
-				if (substr($match, -1, 1) === '.') {
-					$match = substr($match,0,-1);
-				}
-
 					// ignore strictly numeric tags like #1
 					if ((strpos($match, '#') === 0) && ctype_digit(substr($match, 1))) {
 						continue;
@@ -2157,10 +2139,30 @@ class BBCode
 					if (strpos($string, $match) && preg_match('/[a-zA-z0-9\/]/', substr($string, strpos($string, $match) - 1, 1))) {
 						continue;
 					}
+
 					$ret[] = $match;
 				}
 			}
+		});
 
-		return $ret;
+		return array_unique($ret);
+	}
+
+	/**
+	 * Perform a custom function on a text after having escaped blocks enclosed in the provided tag list.
+	 *
+	 * @param string   $text
+	 * @param array    $tagList A list of tag names, e.g ['noparse', 'nobb', 'pre']
+	 * @param callable $callback
+	 * @return string
+	 * @throws Exception
+	 *@see Strings::performWithEscapedBlocks
+	 *
+	 */
+	public static function performWithEscapedTags(string $text, array $tagList, callable $callback)
+	{
+		$tagList = array_map('preg_quote', $tagList);
+
+		return Strings::performWithEscapedBlocks($text, '#\[(?:' . implode('|', $tagList) . ').*?\[/(?:' . implode('|', $tagList) . ')]#ism', $callback);
 	}
 }

src/Content/Text/HTML.php

@@ -167,24 +167,7 @@ class HTML
 	{
 		$message = str_replace("\r", "", $message);
 
-		// Removing code blocks before the whitespace removal processing below
+		$message = Strings::performWithEscapedBlocks($message, '#<pre><code.*</code></pre>#iUs', function ($message) {
-		$codeblocks = [];
-		$message = preg_replace_callback(
-			'#<pre><code(?: class="language-([^"]*)")?>(.*)</code></pre>#iUs',
-			function ($matches) use (&$codeblocks) {
-				$return = '[codeblock-' . count($codeblocks) . ']';
-
-				$prefix = '[code]';
-				if ($matches[1] != '') {
-					$prefix = '[code=' . $matches[1] . ']';
-				}
-
-				$codeblocks[] = $prefix . PHP_EOL . trim($matches[2]) . PHP_EOL . '[/code]';
-				return $return;
-			},
-			$message
-		);
-
 			$message = str_replace(
 				[
 					"<li><p>",
@@ -404,15 +387,18 @@ class HTML
 			// Handling Yahoo style of mails
 			$message = str_replace('[hr][b]From:[/b]', '[quote][b]From:[/b]', $message);
 
-		// Restore code blocks
+			return $message;
+		});
+
 		$message = preg_replace_callback(
-			'#\[codeblock-([0-9]+)\]#iU',
+			'#<pre><code(?: class="language-([^"]*)")?>(.*)</code></pre>#iUs',
-			function ($matches) use ($codeblocks) {
+			function ($matches) {
-				$return = '';
+				$prefix = '[code]';
-				if (isset($codeblocks[intval($matches[1])])) {
+				if ($matches[1] != '') {
-					$return = $codeblocks[$matches[1]];
+					$prefix = '[code=' . $matches[1] . ']';
 				}
-				return $return;
+
+				return $prefix . PHP_EOL . trim($matches[2]) . PHP_EOL . '[/code]';
 			},
 			$message
 		);

src/Model/Item.php

@@ -1780,7 +1780,7 @@ class Item
 
 
 		// Check for hashtags in the body and repair or add hashtag links
-		self::setHashtags($item);
+		$item['body'] = self::setHashtags($item['body']);
 
 		// Fill the cache field
 		self::putInCache($item);
@@ -2424,26 +2424,16 @@ class Item
 		}
 	}
 
-	public static function setHashtags(&$item)
+	public static function setHashtags($body)
 	{
-		$tags = BBCode::getTags($item["body"]);
+		$body = BBCode::performWithEscapedTags($body, ['noparse', 'pre', 'code'], function ($body) {
+			$tags = BBCode::getTags($body);
 
 			// No hashtags?
 			if (!count($tags)) {
-			return false;
+				return $body;
 			}
 
-		// What happens in [code], stays in [code]!
-		// escape the # and the [
-		// hint: we will also get in trouble with #tags, when we want markdown in posts -> ### Headline 3
-		$item["body"] = preg_replace_callback("/\[code(.*?)\](.*?)\[\/code\]/ism",
-			function ($match) {
-				// we truly ESCape all # and [ to prevent gettin weird tags in [code] blocks
-				$find = ['#', '['];
-				$replace = [chr(27).'sharp', chr(27).'leftsquarebracket'];
-				return ("[code" . $match[1] . "]" . str_replace($find, $replace, $match[2]) . "[/code]");
-			}, $item["body"]);
-
 			// This sorting is important when there are hashtags that are part of other hashtags
 			// Otherwise there could be problems with hashtags like #test and #test2
 			// Because of this we are sorting from the longest to the shortest tag.
@@ -2455,29 +2445,29 @@ class Item
 
 			// All hashtags should point to the home server if "local_tags" is activated
 			if (DI::config()->get('system', 'local_tags')) {
-			$item["body"] = preg_replace("/#\[url\=([$URLSearchString]*)\](.*?)\[\/url\]/ism",
+				$body = preg_replace("/#\[url\=([$URLSearchString]*)\](.*?)\[\/url\]/ism",
-					"#[url=".DI::baseUrl()."/search?tag=$2]$2[/url]", $item["body"]);
+					"#[url=" . DI::baseUrl() . "/search?tag=$2]$2[/url]", $body);
 			}
 
 			// mask hashtags inside of url, bookmarks and attachments to avoid urls in urls
-		$item["body"] = preg_replace_callback("/\[url\=([$URLSearchString]*)\](.*?)\[\/url\]/ism",
+			$body = preg_replace_callback("/\[url\=([$URLSearchString]*)\](.*?)\[\/url\]/ism",
 				function ($match) {
 					return ("[url=" . str_replace("#", "#", $match[1]) . "]" . str_replace("#", "#", $match[2]) . "[/url]");
-			}, $item["body"]);
+				}, $body);
 
-		$item["body"] = preg_replace_callback("/\[bookmark\=([$URLSearchString]*)\](.*?)\[\/bookmark\]/ism",
+			$body = preg_replace_callback("/\[bookmark\=([$URLSearchString]*)\](.*?)\[\/bookmark\]/ism",
 				function ($match) {
 					return ("[bookmark=" . str_replace("#", "#", $match[1]) . "]" . str_replace("#", "#", $match[2]) . "[/bookmark]");
-			}, $item["body"]);
+				}, $body);
 
-		$item["body"] = preg_replace_callback("/\[attachment (.*)\](.*?)\[\/attachment\]/ism",
+			$body = preg_replace_callback("/\[attachment (.*)\](.*?)\[\/attachment\]/ism",
 				function ($match) {
 					return ("[attachment " . str_replace("#", "#", $match[1]) . "]" . $match[2] . "[/attachment]");
-			}, $item["body"]);
+				}, $body);
 
 			// Repair recursive urls
-		$item["body"] = preg_replace("/#\[url\=([$URLSearchString]*)\](.*?)\[\/url\]/ism",
+			$body = preg_replace("/#\[url\=([$URLSearchString]*)\](.*?)\[\/url\]/ism",
-				"#$2", $item["body"]);
+				"#$2", $body);
 
 			foreach ($tags as $tag) {
 				if ((strpos($tag, '#') !== 0) || strpos($tag, '[url=') || strlen($tag) < 2 || $tag[1] == '#') {
@@ -2487,21 +2477,16 @@ class Item
 				$basetag = str_replace('_', ' ', substr($tag, 1));
 				$newtag = '#[url=' . DI::baseUrl() . '/search?tag=' . $basetag . ']' . $basetag . '[/url]';
 
-			$item["body"] = str_replace($tag, $newtag, $item["body"]);
+				$body = str_replace($tag, $newtag, $body);
 			}
 
 			// Convert back the masked hashtags
-		$item["body"] = str_replace("&num;", "#", $item["body"]);
+			$body = str_replace("&num;", "#", $body);
 
-		// Remember! What happens in [code], stays in [code]
+			return $body;
-		// roleback the # and [
+		});
-		$item["body"] = preg_replace_callback("/\[code(.*?)\](.*?)\[\/code\]/ism",
+
-			function ($match) {
+		return $body;
-				// we truly unESCape all sharp and leftsquarebracket
-				$find = [chr(27).'sharp', chr(27).'leftsquarebracket'];
-				$replace = ['#', '['];
-				return ("[code" . $match[1] . "]" . str_replace($find, $replace, $match[2]) . "[/code]");
-			}, $item["body"]);
 	}
 
 	/**

src/Model/Notify.php

@@ -70,7 +70,7 @@ class Notify extends BaseModel
 	private function setNameCache()
 	{
 		try {
-			$this->name_cache = strip_tags(BBCode::convert($this->source_name ?? ''));
+			$this->name_cache = strip_tags(BBCode::convert($this->source_name));
 		} catch (InternalServerErrorException $e) {
 		}
 	}

src/Module/Debug/Babel.php

@@ -102,14 +102,12 @@ class Babel extends BaseModule
 						'content' => visible_whitespace($bbcode4)
 					];
 
-					$item = ['body' => $bbcode];
-
 					$tags = Text\BBCode::getTags($bbcode);
 
-					Item::setHashtags($item);
+					$body = Item::setHashtags($bbcode);
 					$results[] = [
 						'title'   => DI::l10n()->t('Item Body'),
-						'content' => visible_whitespace($item['body'])
+						'content' => visible_whitespace($body)
 					];
 					$results[] = [
 						'title'   => DI::l10n()->t('Item Tags'),
@@ -125,9 +123,7 @@ class Babel extends BaseModule
 
 					$markdown = XML::unescape($diaspora);
 				case 'markdown':
-					if (!isset($markdown)) {
+					$markdown = $markdown ?? trim($_REQUEST['text']);
-						$markdown = trim($_REQUEST['text']);
-					}
 
 					$results[] = [
 						'title'   => DI::l10n()->t('Source input (Markdown)'),

src/Util/Strings.php

@@ -472,4 +472,52 @@ class Strings
 
 		return mb_substr($string, 0, $start) . $replacement . mb_substr($string, $start + $length, $string_length - $start - $length);
 	}
+
+	/**
+	 * Perform a custom function on a text after having escaped blocks matched by the provided regular expressions.
+	 * Only full matches are used, capturing group are ignored.
+	 *
+	 * To change the provided text, the callback function needs to return it and this function will return the modified
+	 * version as well after having restored the escaped blocks.
+	 *
+	 * @param string   $text
+	 * @param string   $regex
+	 * @param callable $callback
+	 * @return string
+	 * @throws \Exception
+	 */
+	public static function performWithEscapedBlocks(string $text, string $regex, callable $callback)
+	{
+		// Enables nested use
+		$executionId = random_int(PHP_INT_MAX / 10, PHP_INT_MAX);
+
+		$blocks = [];
+
+		$text = preg_replace_callback($regex,
+			function ($matches) use ($executionId, &$blocks) {
+				$return = '«block-' . $executionId . '-' . count($blocks) . '»';
+
+				$blocks[] = $matches[0];
+
+				return $return;
+			},
+			$text
+		);
+
+		$text = $callback($text) ?? '';
+
+		// Restore code blocks
+		$text = preg_replace_callback('/«block-' . $executionId . '-([0-9]+)»/iU',
+			function ($matches) use ($blocks) {
+				$return = $matches[0];
+				if (isset($blocks[intval($matches[1])])) {
+					$return = $blocks[$matches[1]];
+				}
+				return $return;
+			},
+			$text
+		);
+
+		return $text;
+	}
 }

tests/include/ApiTest.php

@@ -3852,7 +3852,7 @@ class ApiTest extends DatabaseTest
 		$assertXml=<<<XML
 <?xml version="1.0"?>
 <notes>
-  <note id="1" hash="" type="8" name="Reply to" url="http://localhost/display/1" photo="http://localhost/" date="2020-01-01 12:12:02" msg="A test reply from an item" uid="42" uri-id="" link="http://localhost/notification/1" iid="4" parent="0" parent-uri-id="" seen="0" verb="" otype="item" name_cache="" msg_cache="A test reply from an item" timestamp="1577880722" date_rel="{$dateRel}" msg_html="A test reply from an item" msg_plain="A test reply from an item"/>
+  <note id="1" hash="" type="8" name="Reply to" url="http://localhost/display/1" photo="http://localhost/" date="2020-01-01 12:12:02" msg="A test reply from an item" uid="42" uri-id="" link="http://localhost/notification/1" iid="4" parent="0" parent-uri-id="" seen="0" verb="" otype="item" name_cache="Reply to" msg_cache="A test reply from an item" timestamp="1577880722" date_rel="{$dateRel}" msg_html="A test reply from an item" msg_plain="A test reply from an item"/>
 </notes>
 XML;
 		$this->assertXmlStringEqualsXmlString($assertXml, $result);

tests/src/Util/StringsTest.php

@@ -194,4 +194,30 @@ class StringsTest extends TestCase
 			)
 		);
 	}
+
+	public function testPerformWithEscapedBlocks()
+	{
+		$originalText = '[noparse][/noparse][nobb]nobb[/nobb][noparse]noparse[/noparse]';
+
+		$text = Strings::performWithEscapedBlocks($originalText, '#[(?:noparse|nobb)].*?\[/(?:noparse|nobb)]#is', function ($text) {
+			return $text;
+		});
+
+		$this->assertEquals($originalText, $text);
+	}
+
+	public function testPerformWithEscapedBlocksNested()
+	{
+		$originalText = '[noparse][/noparse][nobb]nobb[/nobb][noparse]noparse[/noparse]';
+
+		$text = Strings::performWithEscapedBlocks($originalText, '#[nobb].*?\[/nobb]#is', function ($text) {
+			$text = Strings::performWithEscapedBlocks($text, '#[noparse].*?\[/noparse]#is', function ($text) {
+				return $text;
+			});
+
+			return $text;
+		});
+
+		$this->assertEquals($originalText, $text);
+	}
 }