Merge pull request #1439 from mathjax/issue3532

dpvc · web-flow · commit e2c5e00563be · 2026-03-29T13:11:50.000-04:00
Fix isEmpty to work with partially complete `msubsup` elements with empty bases. (mathjax/MathJax#3532)
diff --git a/ts/core/MmlTree/MmlNode.ts b/ts/core/MmlTree/MmlNode.ts
@@ -546,7 +546,7 @@ export abstract class AbstractMmlNode
    */
   public get isEmpty(): boolean {
     for (const child of this.childNodes) {
-      if (!child.isEmpty) return false;
+      if (child && !child.isEmpty) return false;
     }
     return true;
   }

Original file line number	Diff line number	Diff line change
`@@ -546,7 +546,7 @@ export abstract class AbstractMmlNode`
`546`	`546`	`*/`
`547`	`547`	`public get isEmpty(): boolean {`
`548`	`548`	`for (const child of this.childNodes) {`
`549`		`- if (!child.isEmpty) return false;`
	`549`	`+ if (child && !child.isEmpty) return false;`
`550`	`550`	`}`
`551`	`551`	`return true;`
`552`	`552`	`}`