Query string parameters containing ampersand/equals aren't properly encoded in data-url

[dpolivy]

I've worked with @gabrielschulhof on some issues related to data-url in the past (see #1383), but there's still a lingering issue here with ampersands and equals (see #3099). Specifically, if a URL query string parameter contains an embedded ampersand or equals sign, then data-url is not correctly encoded, and when the URL is updated, the embedded ampersand is interpreted as another parameter, when in fact it should be part of the value for the previous parameter.

I tried to put together this jsbin example showing the error:

http://output.jsbin.com/cononumoze

To use it, just type a string into the box and hit submit. The page will reload and show you the value of various page elements. It's best if you look at this with the Chrome DevTools open to the Network tab. If you enter a query with an ampersand, e.g. Ren & Stimpy, when you hit submit, you'll see it get submitted as /cononumoze?q=ren+%26+stimpy, which is correct. But when the page reloads, the data-url is set as /cononumoze?q=ren+&+stimpy, the URL bar is updated without the %26 encoding, and when one tries to parse the q parameter, you only get Ren.

It's been a little challenging trying to get my head around this, but I'm pretty sure this is a problem with jQM not properly handling the embedded ampersand/equals. The guidance coming out of #1383 was that data-url should NOT be url encoded, and so it goes through a decode pass before being stored. But, I think the embedded ampersand/equals need to stay encoded. I'm not sure how to reliably do this.

This is a pretty critical bug for us, as we legitimately have query parameter values containing ampersands, and basically they are broken for navigation AFTER the original request.

[dpolivy]

I've been looking at this a little, and I wonder if it is sufficient to restate the data-url format to be "NOT urlencoded, except embedded &, +, = characters". Appropriate code modification would be something like this:

https://github.com/jquery/jquery-mobile/blob/d3a412e4f017c15a64fc2b132481f93f47606289/js/navigation/path.js#L219

            return window.decodeURIComponent( result.replace('%26', '%2526').replace('%3D', '%253D').replace('%2B', '%252B') );

A bit of a hack, and there might be other characters that would need to be included here, but it should at least prevent query strings from being completely broken.

Comments?

[arschmitz]

@dpolivy thank you for reporting this that indeed is a bug. Not sure if your fix is really the right one but we will need to figure out what is