> After ‘C-x v g’ (vc-annotate) typing ‘a’ (vc-annotate-revision-previous-to-line)
> in the *Annotate* buffer on the earliest (initial) revision fails with:
>
>   Debugger entered--Lisp error: (error "Invalid argument to vc-annotate-warp-revision")
>     signal(error ("Invalid argument to vc-annotate-warp-revision"))
>     error("Invalid argument to vc-annotate-warp-revision")
>     vc-annotate-warp-revision(nil "...")

This is now fixed.

Another problem is that ‘vc-root-version-diff’ can't be used when
fileset is not available.  But this command doesn't use fileset,
it uses the root directory, so this patch adds an optional
arg ‘fileset’ to ‘vc-diff-build-argument-list-internal’,
so ‘vc-root-version-diff’ can provide its own fake fileset
with the root directory: