Description of problem:
Some queries fetch a list of bug ids and use them in the query, if the number of bugids exceeds 65K it produces a DBI error

Version-Release number of selected component (if applicable):
5.0

How reproducible:
Easy

Steps to Reproduce:
1. visit $server/editgroups.cgi?action=changeform&group=12

Actual results:
DBD::Pg::db selectall_arrayref failed: number of parameters must be between 0 and 65535 [for Statement "SELECT
...
<pre>
 at Bugzilla/Object.pm line 403.
	Bugzilla::Object::_do_list_select("Bugzilla::Bug", " bug_id IN (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?"..., ARRAY(0x8f5fc18), undef) called at Bugzilla/Object.pm line 369
	Bugzilla::Object::match("Bugzilla::Bug", HASH(0x9827358)) called at Bugzilla/Object.pm line 182
	Bugzilla::Object::new_from_list("Bugzilla::Bug", ARRAY(0x8f6c570)) called at Bugzilla/Group.pm line 89
	Bugzilla::Group::bugs(Bugzilla::Group=HASH(0x8d48130)) called at template/en/default/admin/groups/edit.html.tmpl line 86
	eval {...} called at template/en/default/admin/groups/edit.html.tmpl line 86
	eval {...} called at template/en/default/admin/groups/edit.html.tmpl line 18
	Template::Provider::__ANON__(Bugzilla::Template::Context=HASH(0x8a3e728)) called at /usr/lib64/perl5/vendor_perl/Template/Document.pm line 163
	eval {...} called at /usr/lib64/perl5/vendor_perl/Template/Document.pm line 161
	Template::Document::process(Template::Document=HASH(0x8d70a58), Bugzilla::Template::Context=HASH(0x8a3e728)) called at /usr/lib64/perl5/vendor_perl/Template/Context.pm line 351
	eval {...} called at /usr/lib64/perl5/vendor_perl/Template/Context.pm line 321
	Template::Context::process(Bugzilla::Template::Context=HASH(0x8a3e728), Template::Document=HASH(0x8d70a58)) called at Bugzilla/Template/Context.pm line 35
	Bugzilla::Template::Context::process(Bugzilla::Template::Context=HASH(0x8a3e728), Template::Document=HASH(0x8d70a58)) called at /usr/lib64/perl5/vendor_perl/Template/Service.pm line 94
	eval {...} called at /usr/lib64/perl5/vendor_perl/Template/Service.pm line 91
	Template::Service::process(Template::Service=HASH(0x8a377f8), "admin/groups/edit.html.tmpl", HASH(0xceef30)) called at /usr/lib64/perl5/vendor_perl/Template.pm line 66
	Template::process(Bugzilla::Template=HASH(0x8999f18), "admin/groups/edit.html.tmpl", HASH(0xceef30)) called at Bugzilla/Template.pm line 724
	Bugzilla::Template::process(Bugzilla::Template=HASH(0x8999f18), "admin/groups/edit.html.tmpl", HASH(0xceef30)) called at /home/jfearn/public_html/bugzilla-bayot/editgroups.cgi line 159

</pre>
Expected results:
The group edit page loads.

Additional info:
Why does it prefetch the bugiids? Is it just a MySQL optimization or does it filter the bugs outside of the SQL?

Is it possible to raise the limit from 65K, if so what is a sane number?