FUML11 — An activity final node should not fire if it is not offered any tokens

Specification: Semantics of a Foundational Subset for Executable UML Models (fUML) (formal/2011-02-01)

Subclause: 8.5.2.2.3 ActivityFinalNodeActivation

ActivityFinalNodeActivation::fire(incomingTokens) currently terminates the activity node activation group containing the activity final node, even if incomingTokens is empty. This is normally not a problem, since fire is usually only called if at least one token has been offered. However, if the activity final node is in a loop node or a conditional clause with an incoming edge from the body of the loop node or clause, then, when the test for the loop node or clause is being executed, the body part is not yet activated. If the source of the incoming edge to the activity final node is a body part node that is not activated, then the edge will be ignored in determining whether the final node is enabled, resulting in the final node being considered enabled and, unless otherwise prevented, firing prematurely, terminating the enclosing loop node or conditional node.

Agreed. Note that the revised text below also includes a check for the final node having no incoming edges at all (which is valid), so that, in this case, it will fire when enabled, even though it will have no incoming tokens.