R devel - May 2017 - Allow dot in RHS of update.formula's old formula

Feature request:

I want to use update.formula to subtract an intercept (or other) term from a
formula with a dot on the RHS. However, as this causes an error, I propose a
patch below.

Thus, I want:
> update.formula(y ~ ., ~ . -1)
[1] y ~ . - 1

Instead I get this error:
Error in terms.formula(tmp, simplify = TRUE) : 
  '.' in formula and no 'data' argument

While the error message isn't especially helpful (as I *cannot* currently
pass in a data argument), the problem is that terms.formula inside
update.formula does not allow a dot in the RHS of 'old' unless either a
'data' argument is passed in or 'allowDotAsName=TRUE'.

Thus, I'd like to suggest this change to update.formula to allow a dot in
the RHS of old without (I believe) impacting any other behavior.

-    out <- formula(terms.formula(tmp, simplify = TRUE))
+    out <- formula(terms.formula(tmp, simplify = TRUE, allowDotAsName=TRUE))

If this is undesirable for some reason, then alternatively the dots argument of
update.formula could be passed to terms.formula so the user could pass in either
'data' or 'allowDotAsName=TRUE' themselves (though as I cannot
think of any reason the user would prefer 'allowDotAsName=FALSE', this
is not my preference).

-    out <- formula(terms.formula(tmp, simplify = TRUE))
+    out <- formula(terms.formula(tmp, simplify = TRUE, ...))
>From my reading of the Details section of ?update.formula, it seems as if
this suggestion is consistent with the current documentation, as no mention is
made of dots in the RHS of 'old', and no mention is made of why this
behavior should be otherwise prohibited. If neither change is desirable for some
reason, then the update.formula documentation should at least point out this
exception (e.g. "... and substitutes the _rhs_ of the 'old' formula
for any occurrence of '.' on the right of 'new' *except if there
is a dot in the _rhs_ of 'old'*."
Thanks, Robert