fdo#80462: Don't always increment the start row position.

Sometimes someone might attempt to sort only a single row.

Change-Id: Ie29d4cf7ec0bd3a5c945997083368b6ef6074268
fdo#80462: Write test for this.

Change-Id: Icdc83c0264fd76239e8c8772c207cc22ce969a76
Add another test case.

Change-Id: I1664bc3faf44abc978391d0f97820c468f4419b0