On Mon, Sep 21, 2020 at 05:53:32PM +0100, Dave Martin wrote:

> I think the idea with this patch was to make sure that .altmacro is
> only in effect for the internals of _for: it gets turned off again
> before expanding any other macro, and at the end.

Yes, this was my understanding of what this was doing when I looked
through things when taking over the code - if we're going to use a
different macro mode to the rest of the code then it seems sensible to
make sure we don't try to build any other code with that macro mode
otherwise it'll doubtless blow up in our faces at some point.