Flow implementation validation doesn't check if the sequence is properly connected

[lwrage]

Summary

There are cases where validation doesn't discover that the elements in a flow implementation are not connected.

Steps to Reproduce

1. Load the model below into the AADL text editor

package Issue2416
public

    abstract A
        features
            i: in data port;
            o: out data port;
        flows
            fsrc: flow source o;
            fpth: flow path i -> o;
            fsnk: flow sink i;
    end A;

    abstract implementation A.i
        subcomponents
            mm1: abstract A;
            mm2: abstract A;
        connections
            cml: port i -> mm1.i;
            cmm: port mm1.o -> mm2.i;
            cmr: port mm2.o -> o;
        flows
            -- this one is ok
            fpth: flow path i -> cml -> mm1.fpth -> cmm -> mm2.fpth -> cmr -> o;
            -- this one is correctly marked with an error on the second cml
            fpth: flow path i -> cml -> mm1.fpth -> cml -> mm2.fpth -> cmr -> o;
            -- this one is correctly marked with errors on cmr and cmm
            fpth: flow path i -> cml -> mm1.fpth -> cmr -> mm2.fpth -> cmm -> o;
            -- there should be an error that mm1.fpth is not connected to cmr
            fpth: flow path i -> cml -> mm1.fpth -> cmr -> o;
            -- there should be an error that cml is not connected to mm2.fpth
            fpth: flow path i -> cml -> mm2.fpth -> cmr -> o;

            -- ok
            fsrc: flow source mm1.fpth -> cmm -> mm2.fpth -> cmr -> o;
            -- error as expected on cml
            fsrc: flow source mm1.fpth -> cml -> mm2.fpth -> cmr -> o;
            -- there should e an error on cmr
            fsrc: flow source mm1.fpth -> cmr -> o;

            -- ok
            fsnk: flow sink i -> cml -> mm1.fpth -> cmm -> mm2.fpth;
            -- error as expected on cml
            fsnk: flow sink i -> cml -> mm1.fpth -> cml -> mm2.fpth;
            -- there should e an error on cml
            fsnk: flow sink i -> cml -> mm2.fpth;

    end A.i;

end Issue2416;

Environment

• OSATE Version: 2.8.0
• Operating System: all

[lwrage]

It looks like validation works if connection is to a different feature in the component of the flow spec but fails if the connection is to a different component.