Perform delegate cursor enter/exit first

Delegate may fail to perform the operation, which would leave
our stack inconsistent, leading to confusion if the user ignores
exceptions. Perform enter/exit on delegate first and only if it
succeeds proceed to update our stack.

Change-Id: If6ebfd9b530e9052a5dc8cab120a5d0c8317f937
Signed-off-by: Robert Varga <rovarga@cisco.com>
(cherry picked from commit 10787df610669aa4bb22f7f8feae1dc1455dffb8)