Minifying bootstrap 4 beta

[warrenspe]

Minifying this particular bootstrap 4 beta css rule produces the following output:

.navbar-light .navbar-toggler-icon {
  background-image: url("data:image/svg+xml;charset=utf8,%3Csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath stroke='rgba(0, 0, 0, 0.5)' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 7h22M4 15h22M4 23h22'/%3E%3C/svg%3E");
}

.navbar-light .navbar-toggler-icon{background-image:url("data:image/svg+xml;charset=utf8,%3CsvgviewBox=\'003030\'xmlns=\'http://www.w3.org/2000/svg\'%3E%3Cpathstroke=\'rgba(0,0,0,0.5)\'stroke-width=\'2\'stroke-linecap=\'round\'stroke-miterlimit=\'10\'d=\'M47h22M415h22M423h22\'/%3E%3C/svg%3E")}

Which is incorrect. For some reason, the string quotes are not being respected and their contents are being minified.

[ndparker]

Hmm. we had a similar issue some time ago and more or less agreed that urls cannot contain spaces. They have to be escaped.

[warrenspe]

That is generally a fair assumption; though from the example above it isn't necessarily true in all cases. Regardless of the url() function wrapper, I would have expected the string's contents to not to be minimized.

Isn't the biggest issue, but it does make minifying bootstrap using rcssmin a bit unwieldy, as modifying library code potentially makes it harder to upgrade in the future

[madebr]

Me too agrees that spaces in urls have to be escaped.

And so they are in the bootstrap sample. They are enclosed between double quotes.

[ndparker]

@madebr It's not about CSS Syntax, it's about URL quoting: https://tools.ietf.org/html/rfc2397. These data-URLs are plain wrong.

[jsma]

Browsers appear to support spaces in data URLs (as long as they are quoted strings of course). The original data URLs from Bootstrap 4 renders just fine and is what is used in the compiled version of Bootstrap available on their CDN.

rcssmin is taking a URL, which browsers parse just fine, and rendering an invalid data URL, which browsers can't parse at all. csscompressor has the same issue (there is a workaround in the linked issue).

I realize this tool exists to strip whitespace but in this case, rather than stripping whitespace, could rcssmin instead leave as-is or alternatively simply replace with %20? Is there a reason to actively strip whitespace inside URLs? If this were a linting tool I'd expect it to complain about conformity to spec but it's not obvious to me why a minifier tool should quietly and selectively enforce the spec while breaking browser-valid/tolerated CSS in the process.

[ndparker]

Yes, WS inside URLs are supposed to be strippable (so you can insert them for readability).

Said that, I started working on the issue: https://github.com/ndparker/rcssmin/tree/issue8
the C implementation is missing yet, though.

[qwenger]

Hi,

Has there been any progress on this issue?

[ndparker]

No :-(

[ndparker]

Fix released with 1.1.0.