Add copyNode() to ParseUtil and make it save the the nodes in the node lists. Keep track of extra lists that nodes are in so that copies can save to those lists as well.

Author: dpvc

ts/core/MmlTree/MmlNode.ts

@@ -371,6 +371,8 @@ export abstract class AbstractMmlNode extends AbstractNode implements MmlNode {
       for (const child of children) {
         if (child) {
           node.appendChild(child.copy() as MmlNode);
+        } else {
+          node.childNodes.push(null);
         }
       }
     }

ts/input/tex/ParseOptions.ts

@@ -26,6 +26,7 @@ import StackItemFactory from './StackItemFactory.js';
 import {Tags} from './Tags.js';
 import {SubHandlers} from './MapHandler.js';
 import {NodeFactory} from './NodeFactory.js';
+import NodeUtil from './NodeUtil.js';
 import {MmlNode} from '../../core/MmlTree/MmlNode.js';
 import TexParser from './TexParser.js';
 import {defaultOptions, OptionList} from '../../util/Options.js';
@@ -173,6 +174,14 @@ export default class ParseOptions {
       list = this.nodeLists[property] = [];
     }
     list.push(node);
+    if (node.kind !== property) {
+      //
+      // If the list is not just for its kind, record that it is in this list
+      //   so that if it is copied, the copy can also be added to the list.
+      //
+      let lists = (NodeUtil.getProperty(node, 'in-lists') as string || '').split(',').concat(property).join(',');
+      NodeUtil.setProperty(node, 'in-lists', lists);
+    }
   }
 
 

ts/input/tex/ParseUtil.ts

@@ -469,6 +469,18 @@ namespace ParseUtil {
     parser.stack.global.eqnenv = true;
   }
 
+  export function copyNode(node: MmlNode, parser: TexParser): MmlNode  {
+    const tree = node.copy() as MmlNode;
+    const options = parser.configuration;
+    tree.walkTree((n: MmlNode) => {
+      options.addNode(n.kind, n);
+      const lists = (n.getProperty('in-lists') as string || '').split(/,/);
+      for (const list of lists) {
+        options.addNode(list, n);
+      }
+    });
+    return tree;
+  }
 
   /**
    * This is a placeholder for future security filtering of attributes.

ts/input/tex/cases/CasesConfiguration.ts

@@ -93,7 +93,7 @@ export const CasesMethods = {
       parser.Push(parser.itemFactory.create('end').setProperty('name', begin.getName())); // finish eqnarray
       const cases = parser.stack.Top();
       const table = cases.Last as MmlMtable;
-      const original = table.copy() as MmlMtable;
+      const original = ParseUtil.copyNode(table, parser) as MmlMtable;
       const left = cases.getProperty('left');
       EmpheqUtil.left(table, original, left + '\\empheqlbrace\\,', parser, 'numcases-left');
       parser.Push(parser.itemFactory.create('end').setProperty('name', begin.getName()));

ts/input/tex/empheq/EmpheqUtil.ts

@@ -111,7 +111,7 @@ export const EmpheqUtil = {
    * @return {MmlNode}             The resulting mphantom element.
    */
   topRowTable(original: MmlMtable, parser: TexParser): MmlNode {
-    const table = original.copy();
+    const table = ParseUtil.copyNode(original, parser);
     table.setChildren(table.childNodes.slice(0, 1));
     table.attributes.set('align', 'baseline 1');
     return original.factory.create('mphantom', {}, [parser.create('node', 'mpadded', [table],  {width: 0})]);
@@ -130,7 +130,7 @@ export const EmpheqUtil = {
   rowspanCell(mtd: MmlMtd, tex: string, table: MmlMtable, parser: TexParser, env: string) {
     mtd.appendChild(
       parser.create('node', 'mpadded', [
-        this.cellBlock(tex, table.copy(), parser, env),
+        this.cellBlock(tex, ParseUtil.copyNode(table, parser), parser, env),
         this.topRowTable(table, parser)
       ], {height: 0, depth: 0, voffset: 'height'})
     );
@@ -197,7 +197,7 @@ export const EmpheqUtil = {
     const right = empheq.getProperty('right');
     if (left || right) {
       const table = empheq.Last;
-      const original = table.copy();
+      const original = ParseUtil.copyNode(table, parser);
       if (left) this.left(table, original, left, parser);
       if (right) this.right(table, original, right, parser);
     }