[Math Processing Error] when replacing msub by msup in an expression with nested mmultiscripts

Created by: michel2bec

Hi, here a surprising result I just encountered today : The only difference between (A) and (C) is I replaced msub by msup, the difference between (B) and (C) seems to be the mrow.

(A) This works:

<math>
    <mmultiscripts>
        <mmultiscripts>
            <mi>A</mi>
            <mi>B</mi>
            <mprescripts />
            <none />
            <mi>D</mi>
        </mmultiscripts>
        <mrow>
            <mo>(</mo>
            <msub>
                <mi>g</mi>
                <mi>h</mi>
            </msub>
            <mo>)</mo>
        </mrow>
        <mprescripts />
        <none />
        <mi>i</mi>
    </mmultiscripts>
</math>

(B) This works :

<math>
    <mmultiscripts>
        <mmultiscripts>
            <mi>A</mi>
            <mi>B</mi>
            <mprescripts />
            <none />
            <mi>D</mi>
        </mmultiscripts>
        <msup>
            <mi>g</mi>
            <mi>h</mi>
        </msup>
        <mprescripts />
        <none />
        <mi>i</mi>
    </mmultiscripts>
</math>

(C) This yields [Math Processing Error] :

<math>
    <mmultiscripts>
        <mmultiscripts>
            <mi>A</mi>
            <mi>B</mi>
            <mprescripts />
            <none />
            <mi>D</mi>
        </mmultiscripts>
        <mrow>
            <mo>(</mo>
            <msup>
                <mi>g</mi>
                <mi>h</mi>
            </msup>
            <mo>)</mo>
        </mrow>
        <mprescripts />
        <none />
        <mi>i</mi>
    </mmultiscripts>
</math>