Repro:
Layout> 2 columns
Make a new file in each column
Focus the file in column 2
Close the file
Layout> single
Expected result:
left-column file is active
Observed result:
no-open-buffers blank screen is shown in the view area
Repro:
Layout> 2 columns
Make a new file in each column
Focus the file in column 2
Close the file
Layout> single
Expected result:
left-column file is active
Observed result:
no-open-buffers blank screen is shown in the view area
+1 for a change!
As well as for this related problem: Focus after changing window layout