HTTP to HTTPS policy injecting "/Location: https:///" into URL and breaking application

Is there any chance that the client used to make this call isn't a standard browser? Even with an HTTP/1.0 request, most browsers would insert a Host header (though not expressly required). Maybe something like this might help:

when HTTP_REQUEST {
    set host [HTTP::host]
    if { $host eq "" } {
        set host "myapp.domain.com"
    }
    HTTP::respond 302 Location "https://$host[HTTP::uri]"
}

It'll hard code the Host value if it doesn't exist in the request.