Re: moving SCCS later in vc-handled-backends

[Stephen J. Turnbull]

Dan Nicolaescu writes:

 >   > a subtle change in behavior that will be intermittent and possibly
 >   > hard to diagnose.  I've found that it's almost always better to change
 >   > DWIM to "do nothing" as opposed to "do what somebody else means".
 > 
 > Why intermittent?  It's quite deterministic,

Nondeterministic and intermittent are independent concepts.  The user
doesn't care about the former, the latter bugs her mightily.  If you
don't understand the difference, ask dictionary.com, not me.

 > and it matters if and only if the same file is registered by SCCS
 > and another backend.

That's not what the docstring for `vc-responsible-backend' says.  It
claims that there are several circumstances under which the order in
`vc-handled-backends' matters, and *none* of those involve a file that's
registered at all.  See also the documentation for `vc-transfer-file'.

 > SCCS by itself is rare, using both SCCS and another VCS on the same file
 > gotta be even less frequent.

That's why a behavior change will be only intermittently observed.