Broken URL polyfill

[rob-murray]

The URL polyfill has a couple of issues:

1. The check for native URL API is incorrect - it fails on Safari >9 when this has a perfectly good native implementation
2. The polyfill is incomplete and missing (afaict) searchParams

I use pdf.js in an application and the URL web api in various places, on Safari this is broken because the polyfill from this library is used instead of native code (Safari >9 has full implementation i believe) or the other polyfill I include (this fails the check used in this library incorrectly).

Configuration:

• Web browser and its version: Safari >9
• Operating system and its version: Anything
• PDF.js version: latest (v1.8.188)
• Is a browser extension: No

Steps to reproduce the problem:
1.
2.

What is the expected behavior?

If a browser does not have native URL api support then an up to date polyfill is used. If a browser does have native URL api support then the polyfill is not used.

What went wrong?

A browser with native URL api support was forced to use the broken URL polyfill from pdf.js

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

n/a

[Snuffleupagus]

The polyfill is incomplete and missing (afaict) searchParams

For reference, this part is already tracked in issue #8726.

[rob-murray]

Sorry, I missed that one when searching for existing issues... feel free to close this then if its already got an open issue.

[Snuffleupagus]

Sorry, I missed that one when searching for existing issues... feel free to close this then if its already got an open issue.

No worries; #8726 only seem to concern the searchParams issue, but the first part of the current issue would appear separate and thus valid on its own:

The check for native URL API is incorrect - it fails on Safari >9 when this has a perfectly good native implementation

The following checks are used to determine if a browser has native URL support.

pdf.js/src/shared/compatibility.js

Lines 189 to 207 in 5a52ee0

	// Polyfill from https://github.com/Polymer/URL
	/* Any copyright is dedicated to the Public Domain.
	* http://creativecommons.org/publicdomain/zero/1.0/ */
	(function checkURLConstructor() {
	// feature detect for URL constructor
	var hasWorkingUrl = false;
	try {
	if (typeof URL === 'function' &&
	typeof URL.prototype === 'object' &&
	('origin' in URL.prototype)) {
	var u = new URL('b', 'http://a');
	u.pathname = 'c%20d';
	hasWorkingUrl = u.href === 'http://a/c%20d';
	}
	} catch (e) { }
	if (hasWorkingUrl) {
	return;
	}

[rob-murray]

Safari seems to encode the % so u.href above is http://a/c%2520d, as a result that check is false - I don't know why Safari does this and if it is actually incorrect or even if it matters. The implementation of the polyfill in this library evaluates this check to be true, as does chrome, firefox, etc.

// safari
u = new URL('b', 'http://a'); 
u.pathname = 'c%20d'; 
u.href // "http://a/c%2520d"

// chrome
u = new URL('b', 'http://a'); 
u.pathname = 'c%20d'; 
u.href // "http://a/c%20d"

[timvandermeij]

Fixed by #9868.