From eee3bcd47732414ec32c6bc9d05f144d4dd8c81b Mon Sep 17 00:00:00 2001
From: carla-at-wiris <carla@wiris.com>
Date: Fri, 22 Dec 2023 09:21:58 +0100
Subject: [PATCH] fix(viewer): Formulas with '&' symbol not rendereting

Taskid 42230
---
 CHANGES.md                   | 4 ++++
 packages/viewer/src/utils.ts | 6 ++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index e15faaec2..0b84a08bd 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -15,6 +15,10 @@ Last release of this project is was 20th of December 2023.
   - feat: Add method that allows the integration forcing the hand mode.
   - feat(viewer): decode safe mathml
 
+## Unreleased
+
+  - fix(viewer): Formulas containing '&' symbol are not rendered. #KB-42230
+
 ### 8.7.3 2023-11-22
 
   - fix(tinymce): non blur chemtype svg icon 
diff --git a/packages/viewer/src/utils.ts b/packages/viewer/src/utils.ts
index c4a6ac136..5d479fdd8 100644
--- a/packages/viewer/src/utils.ts
+++ b/packages/viewer/src/utils.ts
@@ -21,12 +21,14 @@ function decodeEntities(text: string): string {
 export function htmlEntitiesToXmlEntities(text: string): string {
   text = decodeEntities(text);
 
-  // Replaces the < & > characters to its HTMLEntity to avoid render issues.
+  // Replaces the '<', '&', '>', and '"' characters to its HTMLEntity to avoid render issues.
   text = text.split('"<"').join('"&lt;"')
     .split('">"')
     .join('"&gt;"')
     .split('><<')
-    .join('>&lt;<');
+    .join('>&lt;<')
+    .split('&')
+    .join('&amp;');
 
   let result = '';
   for (let i = 0; i < text.length; i++) {