From a0545f2b449fd73c745c7e50e431c29cc9f3cf7e Mon Sep 17 00:00:00 2001
From: Jon Stovell <jonstovell@gmail.com>
Date: Wed, 21 Oct 2026 16:04:20 -0600
Subject: [PATCH 1/2] Set the [tt] BBCode's type to
 BBCode::TYPE_UNPARSED_CONTENT

Signed-off-by: Jon Stovell <jonstovell@gmail.com>
---
 Sources/BBCode/Tt.php              | 11 +++--------
 Sources/Parsers/MarkdownParser.php |  9 ++++++---
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/Sources/BBCode/Tt.php b/Sources/BBCode/Tt.php
index 32807ea825c..b460ca7c821 100644
--- a/Sources/BBCode/Tt.php
+++ b/Sources/BBCode/Tt.php
@@ -32,20 +32,15 @@ class Tt extends BBCode
 	/**
 	 *
 	 */
-	public ?string $before = '<code class="bbc_tt">';
+	public ?string $type = BBCode::TYPE_UNPARSED_CONTENT;
 
 	/**
 	 *
 	 */
-	public ?string $after = '</code>';
+	public ?string $content = '<code class="bbc_tt">$1</code>';
 
 	/**
 	 *
 	 */
-	public ?string $disabled_before = '';
-
-	/**
-	 *
-	 */
-	public ?string $disabled_after = '';
+	public ?string $disabled_content = '$1';
 }
diff --git a/Sources/Parsers/MarkdownParser.php b/Sources/Parsers/MarkdownParser.php
index c22a5315d11..89cf1344f3b 100644
--- a/Sources/Parsers/MarkdownParser.php
+++ b/Sources/Parsers/MarkdownParser.php
@@ -3403,7 +3403,6 @@ protected function renderCodeBlock(array $element): void
 
 				foreach (BBCodeParser::getCodes() as $code) {
 					if ($code->tag === 'code' && $code->type === $bbc_type) {
-						list($before, $after) = preg_split('/\$1/', $code->content);
 						break;
 					}
 				}
@@ -3412,6 +3411,8 @@ protected function renderCodeBlock(array $element): void
 					$code = $this->disableCode($code);
 				}
 
+				list($before, $after) = preg_split('/\$1/', $code->content);
+
 				$this->rendered .= strtr(
 					$before,
 					[
@@ -4179,7 +4180,9 @@ protected function renderInlineCode(array $element): void
 					$code = $this->disableCode($code);
 				}
 
-				$this->rendered .= $code->before;
+				list($before, $after) = preg_split('/\$1/', $code->content);
+
+				$this->rendered .= $before;
 				break;
 
 			default:
@@ -4197,7 +4200,7 @@ protected function renderInlineCode(array $element): void
 				break;
 
 			case self::OUTPUT_HTML:
-				$this->rendered .= $code->after;
+				$this->rendered .= $after;
 				break;
 
 			default:

From af16edf89fa7fc70a5512a84bd31fcfc803d7f8e Mon Sep 17 00:00:00 2001
From: Jon Stovell <jonstovell@gmail.com>
Date: Wed, 21 Oct 2026 16:58:50 -0600
Subject: [PATCH 2/2] Protects contents of Markdown code blocks and spans from
 other parsers

Signed-off-by: Jon Stovell <jonstovell@gmail.com>
---
 Sources/Parser.php | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/Sources/Parser.php b/Sources/Parser.php
index 7646afe9c9f..f3d92569b78 100644
--- a/Sources/Parser.php
+++ b/Sources/Parser.php
@@ -254,6 +254,18 @@ abstract class Parser
 	 */
 	private static array $results = [];
 
+	/**
+	 * @var array
+	 *
+	 * Placeholders used to protect certain strings from processing
+	 * by other parsers.
+	 */
+	private static array $placeholder_strings = [
+		'bbcode' => [],
+		'smileys' => [],
+		'markdown' => [],
+	];
+
 	/****************
 	 * Public methods
 	 ****************/
@@ -994,6 +1006,11 @@ protected static function toHTML(string $string, int $input_types, array $option
 
 		$input_types = $input_types | ($smileys ? self::INPUT_SMILEYS : 0);
 
+		// Protect the content of Markdown code blocks and spans.
+		if ($input_types & self::INPUT_MARKDOWN) {
+			$string = self::protectMarkdownCode($string);
+		}
+
 		// Parse the BBCode.
 		if ($input_types & self::INPUT_BBC) {
 			$string = BBcodeParser::load(!empty($options['for_print']))->parse($string, !empty($input_types & self::INPUT_SMILEYS), $options['cache_id'], $options['parse_tags']);
@@ -1009,6 +1026,7 @@ protected static function toHTML(string $string, int $input_types, array $option
 
 		// Parse the Markdown.
 		if ($input_types & self::INPUT_MARKDOWN) {
+			$string = strtr($string, self::$placeholder_strings['markdown']);
 			$string = MarkdownParser::load(self::OUTPUT_HTML)->parse($string, true, $options);
 		}
 
@@ -1338,4 +1356,36 @@ protected static function fixTag(string $message, string $tag, array $protocols,
 
 		return $message;
 	}
+
+	/**
+	 * Replaces the contents of Markdown code blocks and spans with placeholders
+	 * to protect them from being parsed by BBCodeParser and/or SmileyParser.
+	 *
+	 * @param string $string A string that might contain Markdown code.
+	 * @return string Updated version of the string.
+	 */
+	protected static function protectMarkdownCode(string $string): string
+	{
+		$string = preg_replace_callback(
+			'/(?<!`)`([^`]*)`(?!`)/',
+			function ($matches) {
+				self::$placeholder_strings['markdown'][md5($matches[1])] = $matches[1];
+
+				return '`' . md5($matches[1]) . '`';
+			},
+			$string,
+		);
+
+		$string = preg_replace_callback(
+			'/(?<!`)(`{3,})([^\n]*)(\X*?)(`{3,})/',
+			function ($matches) {
+				self::$placeholder_strings['markdown'][md5($matches[2])] = $matches[2];
+
+				return $matches[1] . md5($matches[2]) . $matches[3];
+			},
+			$string,
+		);
+
+		return $string;
+	}
 }