Splitting <th> produces a <td> instead of a second <th>

[shri046]

Insert the following table into the editor on the demo page

<table width="200" cellspacing="1" cellpadding="1" border="1">
    <thead>
        <tr>
            <th scope="col" colspan="2">&nbsp;&nbsp;&nbsp;</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
        </tr>
        <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
        </tr>
    </tbody>
</table>

Splitting the header cell horizontally produces a <td> within the <thead> as opposed to <th> as shown below

<table width="200" cellspacing="1" cellpadding="1" border="1">
    <thead>
        <tr>
            <th scope="col">&nbsp;&nbsp;&nbsp;</th>
            <td>&nbsp;</td>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
        </tr>
        <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
        </tr>
    </tbody>
</table>

[alfonsoml]

Proposed patch

[alfonsoml]

I've attached a patch that fixes the problem.

It's just replacing the createElement( 'td' ) with createElement( currentCell.nodeName ) in the splitting functions, but I've included other minor changes to simplify some other code (so fixing later #1865 might be a little easier) or fix a typo.

[alfonsoml]

Fixed with [2373]