Ordered call issue with invocations with same arguments in MockSequence

[drieseng]

When multiple invocations with the same arguments are defined consecutive on a mock, then the last matching method call is used instead of the method call corresponding with the current sequence step.

This is because while scanning for a matching method call, the sequence step is incremented on each match. This causes subsequent method calls with matching arguments - even though their sequence step is higher then the current step - to be considered as candidate.

I've added the following test which currently fails on the first assert (Expected: 101, Actual: 102):

    [Fact]
    public void SameMockRightSequenceMultipleInvocationsWithSameArguments()
    {
        var a = new Mock<IFoo>(MockBehavior.Strict);

        var sequence = new MockSequence();
        a.InSequence(sequence).Setup(x => x.Do(100)).Returns(101);
        a.InSequence(sequence).Setup(x => x.Do(100)).Returns(102);
        a.InSequence(sequence).Setup(x => x.Do(200)).Returns(201);
        a.InSequence(sequence).Setup(x => x.Do(100)).Returns(103);

        Assert.Equal(101, a.Object.Do(100));
        Assert.Equal(102, a.Object.Do(100));
        Assert.Equal(201, a.Object.Do(200));
        Assert.Equal(103, a.Object.Do(100));
    }

I'll provide a PR which adds this test, and the corresponding fix.

[kzu]

@jdom could you review this quickly?