HTTP::Config->match generates "uninitialized value" in matching method [rt.cpan.org #115670]

Migrated from rt.cpan.org#115670 (status was 'new')

Requestors:

• branislav.zahradnik@gooddata.com

From branislav.zahradnik@gooddata.com on 2016-06-28 13:24:50:

Use case: LWP::UserAgent response redirect handler with matching
specific response header, eg "Client-Warning"

Current code:
    m_header__ => sub {
        my($v, $k, $uri, $request, $response) = @_;
        return unless $request;
        return 1 if $request->header($k) eq $v;
        return 1 if $response && $response->header($k) eq $v;
        return 0;
    },

Quick fix:

    m_header__ => sub {
        my($v, $k, $uri, $request, $response) = @_;
        return unless $request;
        return 1 if $request->header($k) && $request->header($k) eq $v;
        return 1 if $response && $response->header($k) &&
$response->header($k) eq $v;
        return 0;
    },

or just disable warnings in those lamdas.

Start at HTTP::Config->match and reproduce the LWP::UserAgent response-redirect case using a specific response header such as "Client-Warning". Verify matching when request or response headers are absent; done means the match completes without an "uninitialized value" warning while preserving the expected header match.