fix: MathML \lim\limits in Safari (#2556)

Co-authored-by: ylemkimon <y@ylem.kim>

src/functions/op.js

@@ -164,7 +164,7 @@ const mathmlBuilder: MathMLBuilder<"op"> = (group, options) => {
         const operator = new mathMLTree.MathNode("mo",
             [mml.makeText("\u2061", "text")]);
         if (group.parentIsSupSub) {
-            node = new mathMLTree.MathNode("mo", [node, operator]);
+            node = new mathMLTree.MathNode("mrow", [node, operator]);
         } else {
             node = mathMLTree.newDocumentFragment([node, operator]);
         }

src/functions/operatorname.js

@@ -130,7 +130,7 @@ const mathmlBuilder: MathMLBuilder<"operatorname"> = (group, options) => {
         [mml.makeText("\u2061", "text")]);
 
     if (group.parentIsSupSub) {
-        return new mathMLTree.MathNode("mo", [identifier, operator]);
+        return new mathMLTree.MathNode("mrow", [identifier, operator]);
     } else {
         return mathMLTree.newDocumentFragment([identifier, operator]);
     }

src/functions/supsub.js

@@ -260,7 +260,12 @@ defineFunctionBuilders({
             }
         }
 
-        const node = new mathMLTree.MathNode(nodeType, children);
+        let node = new mathMLTree.MathNode(nodeType, children);
+
+        if (group.base && (group.base.type === "op" ||
+            group.base.type === "operatorname")) {
+            node = new mathMLTree.MathNode("mo", [node]);
+        }
 
         return node;
     },

test/__snapshots__/mathml-spec.js.snap

@@ -308,15 +308,16 @@ exports[`A MathML builder should output \\limsup_{x \\rightarrow \\infty} correc
 <math xmlns="http://www.w3.org/1998/Math/MathML">
   <semantics>
     <mrow>
-      <msub>
       <mo>
+        <msub>
+          <mrow>
             <mi mathvariant="normal">
               lim sup
             </mi>
             <mo>
               ⁡
             </mo>
-        </mo>
+          </mrow>
           <mrow>
             <mi>
               x
@@ -329,6 +330,7 @@ exports[`A MathML builder should output \\limsup_{x \\rightarrow \\infty} correc
             </mi>
           </mrow>
         </msub>
+      </mo>
     </mrow>
     <annotation encoding="application/x-tex">
       \\limsup_{x \\rightarrow \\infty}
@@ -343,15 +345,16 @@ exports[`A MathML builder should output \\limsup_{x \\rightarrow \\infty} in dis
 >
   <semantics>
     <mrow>
-      <munder>
       <mo>
+        <munder>
+          <mrow>
             <mi mathvariant="normal">
               lim sup
             </mi>
             <mo>
               ⁡
             </mo>
-        </mo>
+          </mrow>
           <mrow>
             <mi>
               x
@@ -364,6 +367,7 @@ exports[`A MathML builder should output \\limsup_{x \\rightarrow \\infty} in dis
             </mi>
           </mrow>
         </munder>
+      </mo>
     </mrow>
     <annotation encoding="application/x-tex">
       \\limsup_{x \\rightarrow \\infty}
@@ -420,6 +424,7 @@ exports[`A MathML builder should render mathchoice as if there was nothing 1`] =
               displaystyle="true"
       >
         <mrow>
+          <mo>
             <munderover>
               <mo>
                 ∑
@@ -439,6 +444,7 @@ exports[`A MathML builder should render mathchoice as if there was nothing 1`] =
                 ∞
               </mi>
             </munderover>
+          </mo>
           <msup>
             <mi>
               x
@@ -461,6 +467,7 @@ exports[`A MathML builder should render mathchoice as if there was nothing 2`] =
 <math xmlns="http://www.w3.org/1998/Math/MathML">
   <semantics>
     <mrow>
+      <mo>
         <msubsup>
           <mo>
             ∑
@@ -480,6 +487,7 @@ exports[`A MathML builder should render mathchoice as if there was nothing 2`] =
             ∞
           </mi>
         </msubsup>
+      </mo>
       <msup>
         <mi>
           x
@@ -695,6 +703,7 @@ exports[`A MathML builder should use <msupsub> for integrals 1`] = `
       <mstyle scriptlevel="0"
               displaystyle="true"
       >
+        <mo>
           <msubsup>
             <mo>
               ∫
@@ -706,9 +715,11 @@ exports[`A MathML builder should use <msupsub> for integrals 1`] = `
               b
             </mi>
           </msubsup>
+        </mo>
         <mo>
           +
         </mo>
+        <mo>
           <msubsup>
             <mo>
               ∯
@@ -720,9 +731,11 @@ exports[`A MathML builder should use <msupsub> for integrals 1`] = `
               b
             </mi>
           </msubsup>
+        </mo>
         <mo>
           +
         </mo>
+        <mo>
           <msubsup>
             <mo>
               ∰
@@ -734,6 +747,7 @@ exports[`A MathML builder should use <msupsub> for integrals 1`] = `
               b
             </mi>
           </msubsup>
+        </mo>
       </mstyle>
     </mrow>
     <annotation encoding="application/x-tex">
@@ -750,6 +764,7 @@ exports[`A MathML builder should use <msupsub> for regular operators 1`] = `
       <mstyle scriptlevel="0"
               displaystyle="false"
       >
+        <mo>
           <msubsup>
             <mo>
               ∑
@@ -761,6 +776,7 @@ exports[`A MathML builder should use <msupsub> for regular operators 1`] = `
               b
             </mi>
           </msubsup>
+        </mo>
       </mstyle>
     </mrow>
     <annotation encoding="application/x-tex">
@@ -777,6 +793,7 @@ exports[`A MathML builder should use <munderover> for large operators 1`] = `
       <mstyle scriptlevel="0"
               displaystyle="true"
       >
+        <mo>
           <munderover>
             <mo>
               ∑
@@ -788,6 +805,7 @@ exports[`A MathML builder should use <munderover> for large operators 1`] = `
               b
             </mi>
           </munderover>
+        </mo>
       </mstyle>
     </mrow>
     <annotation encoding="application/x-tex">