backslashes get over-escaped in expressions

[jcmf]

Javascript expressions seem to be double-escaped somehow. For example, if I try to make a regular expression literal that matches a literal dot, I end up with something that instead matches a literal backslash followed by any character:

> console.log(src)
.url #{result.u.replace('http://', '').replace(/^www\./, '')}
undefined
> console.log(jade.compile(src, {client: true, compileDebug: false}).toString()) 
function anonymous(locals, attrs, escape, rethrow, merge) {
attrs = attrs || jade.attrs; escape = escape || jade.escape; rethrow = rethrow || jade.rethrow; merge = merge || jade.merge;
var buf = [];
with (locals || {}) {
var interp;
buf.push('<div class="url">' + escape((interp = result.u.replace('http://', '').replace(/^www\\./, '')) == null ? '' : interp) + '</div>');
}
return buf.join("");
}
undefined

I see a bunch of recent backslash-related activity, including #731, not sure whether or how this is related exactly.

[tj]

patching this up