Description:
------------
pecl_http version 1.7.3

http_build_url() replaces "." in query string parameter names with "_" when using the HTTP_URL_JOIN_QUERY option.

This behavior is different than http_build_string() which does not perform this replacement, and the replacement does not occur when replacing the query string entirely.

Test script:
---------------
$url = 'http://www.example.com/foobar?bar.baz=blah&utm_source=google&utm_campaign=somethingelse&blat';

// Original
echo $url, PHP_EOL, PHP_EOL;

// Changing a parameter in the string
echo http_build_url($url, array('query' => 'utm_source=changed'), HTTP_URL_JOIN_QUERY), PHP_EOL, PHP_EOL;

// Replacing the host
echo http_build_url($url, array('host' => 'www.google.com')), PHP_EOL, PHP_EOL;

// Generating a query string from scratch
echo http_build_str(array(
            'bar.baz' => 'blah',
            'utm_source' => 'google',
            'utm_campaign' => 'somethingelse',
            'blat' => null,
            )), PHP_EOL, PHP_EOL;


Expected result:
----------------
// Original
http://www.example.com/foobar?bar.baz=blah&utm_source=google&utm_campaign=somethingelse&blat

// bar.baz should be as originally entered, 'utm_source' updated with new value
http://www.example.com/foobar?bar.baz=blah&utm_source=changed&utm_campaign=somethingelse&blat=

// Host replaced, query string untouched
http://www.google.com/foobar?bar.baz=blah&utm_source=google&utm_campaign=somethingelse&blat

// Query string replaced as-is, no . conversion
http://www.example.com/foobar?blah.foo=baz

// Query string generated, no . conversion
bar.baz=blah&utm_source=google&utm_campaign=somethingelse&blat=

Actual result:
--------------
// Original
http://www.example.com/foobar?bar.baz=blah&utm_source=google&utm_campaign=somethingelse&blat

// BUGBUG: utm_source updated, but bar.baz (which was not touched in the parameters) was replaced with bar_baz
http://www.example.com/foobar?bar_baz=blah&utm_source=changed&utm_campaign=somethingelse&blat=

// Host replaced, query string untouched
http://www.google.com/foobar?bar.baz=blah&utm_source=google&utm_campaign=somethingelse&blat

// Query string replaced as-is, no . conversion
http://www.example.com/foobar?blah.foo=baz

// Query string generated, no . conversion
bar.baz=blah&utm_source=google&utm_campaign=somethingelse&blat=