ConvertUrlElementFinderModifier may fail when parse_url() accepts an invalid URL

[SergeiMV]

In recent versions of guzzlehttp/psr7, the Uri class performs stricter validation of the input data. For example, this behavior can be observed starting from version 2.10.2:

https://github.com/guzzle/psr7/releases/tag/2.10.2

This may cause an issue in ConvertUrlElementFinderModifier.

The modifier currently uses parse_url() to validate URLs before passing them to GuzzleHttp\Psr7\Uri:

$isValid = parse_url($relative) !== false;

if ($isValid) {
    $url = UriResolver::resolve($affected, new Uri($relative))->__toString();
}

However, parse_url() may accept values that are subsequently rejected by GuzzleHttp\Psr7\Uri.

For example:

"http://test test"

parse_url() does not reject this value, so $isValid is true. However, when the same value is passed to:

new Uri('http://test test')

an exception is thrown due to the stricter validation performed by Uri. As a result, the exception is not handled by ConvertUrlElementFinderModifier and the processing of the entire page fails.

There are also cases where an otherwise valid URL contains trailing whitespace, for example:

"http://validurl.com "

These cases could potentially be handled by trimming the value before validation and processing:

$relative = trim($relative);