From 71088fca99af99ff9473de26788638e10fca4ad8 Mon Sep 17 00:00:00 2001
From: 01zulfi <85733202+01zulfi@users.noreply.github.com>
Date: Mon, 13 Apr 2026 20:35:57 +0500
Subject: [PATCH] editor: handle crash on inserting incorrect syntax in math
 nodes (#9690)

* editor: handle crash on inserting incorrect syntax in math nodes
Signed-off-by: 01zulfi <85733202+01zulfi@users.noreply.github.com>

* editor: fix 'math error' text shown on newly empty math node
Signed-off-by: 01zulfi <85733202+01zulfi@users.noreply.github.com>
---
 .../extensions/math/plugin/math-node-view.ts  |  2 ++
 .../extensions/math/plugin/renderers/katex.ts | 32 +++++++++++++------
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/packages/editor/src/extensions/math/plugin/math-node-view.ts b/packages/editor/src/extensions/math/plugin/math-node-view.ts
index 8704299e7..c04ba0abb 100644
--- a/packages/editor/src/extensions/math/plugin/math-node-view.ts
+++ b/packages/editor/src/extensions/math/plugin/math-node-view.ts
@@ -276,6 +276,8 @@ export class MathView implements NodeView, ICursorPosObserver {
       while (this._mathRenderElt.firstChild) {
         this._mathRenderElt.firstChild.remove();
       }
+      this._mathRenderElt.classList.remove("parse-error");
+      this.dom.setAttribute("title", "");
       // do not render empty math
       return;
     } else {
diff --git a/packages/editor/src/extensions/math/plugin/renderers/katex.ts b/packages/editor/src/extensions/math/plugin/renderers/katex.ts
index 1a9b2aa75..47241f98f 100644
--- a/packages/editor/src/extensions/math/plugin/renderers/katex.ts
+++ b/packages/editor/src/extensions/math/plugin/renderers/katex.ts
@@ -32,20 +32,32 @@ async function loadKatex() {
 export const KatexRenderer: MathRenderer = {
   inline: (text, element) => {
     loadKatex().then((katex) => {
-      katex.render(text, element, {
-        displayMode: false,
-        globalGroup: true,
-        throwOnError: false
-      });
+      try {
+        katex.render(text, element, {
+          displayMode: false,
+          globalGroup: true,
+          throwOnError: false
+        });
+      } catch (err) {
+        console.error(err);
+        element.classList.add("parse-error");
+        element.setAttribute("title", err instanceof Error ? err.message : String(err));
+      }
     });
   },
   block: (text, element) => {
     loadKatex().then((katex) => {
-      katex.render(text, element, {
-        displayMode: true,
-        globalGroup: true,
-        throwOnError: false
-      });
+      try {
+        katex.render(text, element, {
+          displayMode: true,
+          globalGroup: true,
+          throwOnError: false
+        });
+      } catch (err) {
+        console.error(err);
+        element.classList.add("parse-error");
+        element.setAttribute("title", err instanceof Error ? err.message : String(err));
+      }
     });
   }
 };