Make sure explicit attributes added by \mmlToken are not removed, eve…

…n if they equal the defaults. (mathjax/MathJax#2806)
mathjax · Jan 18, 2022 · ecb740e · ecb740e
1 parent 6b38558
commit ecb740e
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/ts/input/tex/FilterUtil.ts b/ts/input/tex/FilterUtil.ts
@@ -71,8 +71,10 @@ namespace FilterUtil {
       if (!attribs) {
         return;
       }
+      const keep = new Set((attribs.get('mjx-keep-attrs') || '').split(/ /));
+      delete (attribs.getAllAttributes())['mjx-keep-attrs'];
       for (const key of attribs.getExplicitNames()) {
-        if (attribs.attributes[key] === mml.attributes.getInherited(key)) {
+        if (!keep.has(key) && attribs.attributes[key] === mml.attributes.getInherited(key)) {
           delete attribs.attributes[key];
         }
       }

diff --git a/ts/input/tex/base/BaseMethods.ts b/ts/input/tex/base/BaseMethods.ts
@@ -706,6 +706,7 @@ BaseMethods.MmlToken = function(parser: TexParser, name: string) {
   let attr = parser.GetBrackets(name, '').replace(/^\s+/, '');
   const text = parser.GetArgument(name);
   const def: EnvList = {};
+  const keep: string[] = [];
   let node: MmlNode;
   try {
     node = parser.create('node', kind);
@@ -738,9 +739,13 @@ BaseMethods.MmlToken = function(parser: TexParser, name: string) {
         value = false;
       }
       def[match[1]] = value;
+      keep.push(match[1]);
     }
     attr = attr.substr(match[0].length);
   }
+  if (keep.length) {
+    def['mjx-keep-attrs'] = keep.join(' ');
+  }
   const textNode = parser.create('text', text);
   node.appendChild(textNode);
   NodeUtil.setProperties(node, def);