JavaScript error when inserting new column in the table

[Piotrek Koszuliński]

V4's version of ticket which we had in v3: #8295.

Insert the following code:

<table border="1" cellpadding="1" cellspacing="1" style="width: 500px;">
	<tbody>
		<tr>
			<td>
				1.1</td>
			<td>
				1.2</td>
		</tr>
		<tr>
			<td>
				2.1</td>
			<td>
				2.2</td>
		</tr>
		<tr>
			<td>
				3.1</td>
			<td>
				3.2</td>
		</tr>
	</tbody>
</table>

Go to cell 1.2, right click and choose Cell->Insert Cell Before.

Keep cursor in cell 1.2 right click and choose Column->Insert Column Before/After.

Issue: JS error is thrown and error message: 'colSpan' is null or not an object.

[Olek Nowodziński]

• Created branches t/9609@cksource and t/9609@tests-v4.
• Ported v3 solution with test cases.
• Created #9614 ticket for "insert column before" behavior concerns.

[Olek Nowodziński]

• ​Masterized dev branch.
• Masterized tests-v4 branch: 6458008