From: Marcel Werk <burntime@woltlab.com>
Date: Sun, 28 Mar 2021 10:48:19 +0000 (+0200)
Subject: Made sure ids in toc are unique
X-Git-Tag: 5.3.6~43
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8d77e09bc110b523b9e7fef218dae8b0898771d5;p=GitHub%2FWoltLab%2FWCF.git

Made sure ids in toc are unique
---

diff --git a/wcfsetup/install/files/lib/system/html/toc/HtmlToc.class.php b/wcfsetup/install/files/lib/system/html/toc/HtmlToc.class.php
index 436b1c1945..5d21c4ac4b 100644
--- a/wcfsetup/install/files/lib/system/html/toc/HtmlToc.class.php
+++ b/wcfsetup/install/files/lib/system/html/toc/HtmlToc.class.php
@@ -23,6 +23,7 @@ class HtmlToc {
 		$titleRegex = new Regex('[^\p{L}\p{N}]+', Regex::UTF_8);
 		
 		// fetch all headings in their order of appearance
+		$usedIDs = [];
 		/** @var HtmlTocItem[] $headings */
 		$headings = [];
 		/** @var \DOMElement $hElement */
@@ -38,7 +39,16 @@ class HtmlToc {
 			// trim to 80 characters
 			$id = rtrim(mb_substr($id, 0, 80), '-');
 			$id = mb_strtolower($id);
-			
+			if (isset($usedIDs[$id])) {
+				$i = 2;
+				do {
+					$newID = $id . '--' . ($i++);
+				}
+				while (isset($usedIDs[$newID]));
+				$id = $newID;
+			}
+			$usedIDs[$id] = $id;
+
 			// Using the 'normalized' title allows for human-readable anchors that will remain
 			// valid even when new headings are being added or existing ones are removed. This
 			// also covers the relocation of a heading to a new position.