bugs with variable assignments

[Solid Hogan <dhog@cs.su.oz.au>]

In the process of changing to 1.1gamma, we've found some surprises.
It's probably at least a bit fair to call some of them bugs.

One of the things that makes rc much better than other shells
is the fact that it has true local variables: if you want a
variable to be declared for a local scope, you just

	var=() {
		any code
		you like
	}

and the variable will be saved and restored around the local use.
This is great.

Now, it was a little surprising that this actually failed if there
were nothing but an assignment in the block:

	frag = /a/very/long/pathname/fragment {
		global = ($frag/sub1 $frag/sub2 $frag/third/sub)
	}

never worked (it always left frag set, instead of making the
assignment local).  But in earlier rc's, you could write:

	frag = /a/very/long/pathname/fragment {
		global = ($frag/sub1 $frag/sub2 $frag/third/sub) ;
	}

and it would work.  We're not quite sure where it changed, but it
definitely worked in 1.0.  In 1.1gamma, this no longer works; to get
it to be a local assignment now takes something like:

	frag = /a/very/long/pathname/fragment {
		global = ($frag/sub1 $frag/sub2 $frag/third/sub) true
	}

which is pretty ugly.