When sorting a range of rows (or columns), Calc ignores empty cells at the beginning and the end of the range - as though the range were smaller. There is some fine-tuning of this behavior - controlling whether or not cells with comments or images are considered empty - but we _cannot_ just forego it altogether. We should be able to do so, telling Calc not to second-guess our choice of range, and just "do what it was told".
There are two ways to sort: using the "Sort Ascending" / "Sort Descending" commands or using the "Sort" dialog. If I select a cell range that contains empty rows, they are sorted with the "Sort" dialog (mode sorting rows). Notice, that empty cell always placed after cells with content for to be compatible with Excel. If you use the commands, then auto-detection of used content area is purpose. If you do not want auto-detection, then use the "Sort" dialog.
Considering what I've figured out after reading bug 168905, I'm going to resolve this as INVALID for now.