Problems with -f option and checkout

[John McNamara]

I am trying to use the -f option to check out the head revision if the
tag specified by -r is not found. 

>From the manual:
    Checkout options
        -f Only useful with the `-D date' or `-r tag' flags.
           If no matching revision is found, retrieve the most
           recent revision (instead of ignoring the file). 

I tried the following cases:
    cvs co -f -r TAG1 myfile.c
    cvs co -f -r TAG2 myfile.c
    cvs co -f -r TAG3 myfile.c

Where:
    TAG1 is a valid tag for myfile.c
    TAG2 is a non-existent tag.
    TAG3 is a valid tag but not for myfile.c.

With cvs version 1.10.7 I get the following:
    Case 1. The code checks out.
    Case 2. The code doesn't check out.
    Case 3. The code checks out.

Why doesn't Case 2 work?
If Case 2 shouldn't work why does Case 3 work?

Is this a bug with the cvs -f option or am I missing something? 

John.
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