URLs with commas in query string aren't delivered as boosted

Problem/Motivation

URLs with commas in query string aren't delivered as boosted. For instance, pager querys look like

http:/x.com/node?page=0,1

This causes the page to always be rebuilt and never delivered as boosted.

Here's the watchdog entry.

Array
(
    [scheme] => http
    [host] => forbin
    [path] => actual-proof-2011-06-25
    [query] => page=0%2C1
    [full_path] => actual-proof-2011-06-25
    [base_path] => /gongawaremedia/
    [query_array] => Array
        (
            [page] => 0,1
        )

    [query_extra] =>
    [url_full] => forbin/gongawaremedia/actual-proof-2011-06-25_page=0%2C1
    [url] => http://forbin/gongawaremedia/actual-proof-2011-06-25?page=0%2C1
    [url_decoded] => /gongawaremedia/actual-proof-2011-06-25_page=0,1
    [base_dir] => cache/normal/forbin/gongawaremedia/
    [filename] => cache/normal/forbin/gongawaremedia/actual-proof-2011-06-25_page=0%2C1.html
    [directory] => cache/normal/forbin/gongawaremedia
    [normal_path] => node/68
    [path_alias] => actual-proof-2011-06-25
    [args] => Array
        (
            [0] => node
            [1] => 68
            [2] =>
        )

    [menu_item] => Array
        (
            [page_type] => node_gallery_gallery
            [page_id] => 68
            [path] => node/%
            [load_functions] => Array
                (
                    [1] => node_load
                )

            [to_arg_functions] =>
            [access_callback] => node_access
            [access_arguments] => a:2:{i:0;s:4:"view";i:1;i:1;}
            [page_callback] => node
            [delivery_callback] =>
            [fit] => 2
            [number_parts] => 2
            [context] => 0
            [tab_parent] =>
            [tab_root] => node/%
            [title] => Actual Proof - 2011-06-25
            [title_callback] => node_page_title
            [title_arguments] => a:1:{i:0;i:1;}
            [theme_callback] =>
            [theme_arguments] => Array
                (
                )

            [type] => 6
            [description] =>
            [position] =>
            [weight] => 0
            [include_file] =>
            [href] => node/68
            [tab_root_href] => node/68
            [tab_parent_href] =>
            [options] => Array
                (
                )

            [access] => 1
            [localized_options] => Array
                (
                )

            [original_map] => Array
                (
                    [0] => node
                    [1] => 68
                )

            [status] => 200
            [extra_arguments] =>
        )

    [is_cacheable] => 1
    [header_info] => Array
        (
            [status] => 200 OK
            [status-number] => 200
            [content-type] => text/html; charset=utf-8
            [content-type-basic] => text/html
            [charset] => utf-8
            [headers_sent] =>
        )

    [matched_header_info] => Array
        (
            [enabled] => 1
            [gzip] => 1
            [extension] => html
            [lifetime_max] => 518400
            [lifetime_min] => 0
            [comment_start] => <!--
            [comment_end] => -->
        )

)

Proposed resolution

1. Use a "hack" in boost_exit() that creates two copies of the file. (See comment #4)