In the file: /www/doc/sql/display-sql.tcl

After the first check (for *..*) has been completed, add:
if {[exists_and_not_null package_key]} {
    set safe_p [regexp {/?(.*)} $url package_url]
} else {
    set safe_p [regexp {doc/(.*)} $url doc_url]
}

if {! $safe_p} {
    ad_return_error "Invalid file location" "Can only display files in
package or doc directory"
    return
}

Replace
  ns_returnfile 200 text/plain "[ns_info pageroot]$url"
with
  ns_returnfile 200 text/plain "[ns_info pageroot]/$doc_url"

Replace
  ns_returnfile 200 text/plain "[acs_package_root_dir $package_key]$url"
with
  ns_returnfile 200 text/plain "[acs_package_root_dir
$package_key]/$package_url"