Code folding is broken after using Ctrl-Alt-- to fold a current region

[thehogfather]

Code folding is broken after using Keyboard shortcut to fold the current code region nearest to the cursor.

To reproduce:

1. Open a file with foldable code regions.
2. Navigate inside one of the code regions and press Ctrl-Alt-- to collapse the region.
3. Navigate out of the region and click the gutter to fold a different region.

Result: Nothing happens

1. Put the cursor back on the folded region and press Ctrl-Alt-+ (or click on the gutter for the folded region). This should expand that region.
2. Click on the gutter for any other line in the file.

Result: The code region folded by the shortcut is folded again.