Selection is not cleared after undo to an empty alignment

Scenario:

1. Open "..\general_common_data\fasta\empty.fa".
2. Make sure nothing is selected in the Project View. Click the "Align sequence to this alignment" button on the toolbar.
   Expected state: the file selection dialog is opened.
3. Select "..\samples\CLUSTALW\COI.aln" in the dialog.
   Expected state: the sequences from the file have been added and are shown in the Alignment Editor window.
4. Select a sequence.
5. Click the "Undo" button.
   Expected state: the selection has been cleared.
   Current state: the selection hasn't been cleared. Editing actions (for example, renaming, copying) are enabled. Attempts to use these actions lead to SAFE_POINTs.