CSS Minify: Removal of percentage sign breaks gallery block

[bndn]

My gallery block works great when I’m logged in, but it’s broken for visitors which load minified CSS.

W3 Total Cache CSS Minifier remove a percentage sign from the CSS flex property of an image block in the gallery block.

When CSS is not minified:

# /wp-includes/blocks/gallery/style.min.css
.wp-block-gallery.has-nested-images.is-cropped figure.wp-block-image:not(#individual-image) a, .wp-block-gallery.has-nested-images.is-cropped figure.wp-block-image:not(#individual-image) img {
  flex: 1 0 0%;
  …

When CSS is minified:

.wp-block-gallery.has-nested-images.is-cropped figure.wp-block-image:not(#individual-image) a, .wp-block-gallery.has-nested-images.is-cropped figure.wp-block-image:not(#individual-image) img {
  flex: 1 0 0;
  …

But flex-basis have a different behaviour with 0% and 0px.

[jacobd91]

@bndn

I have been unable to replicate this issue under the latest version of W3 Total Cache (2.8.4) using only the Minify module with the Disk Enhanced engine selected

Could you please provide more details pertaining to your configuration?

Specifically

• W3 Total Cache version
• Other modules active and configured (Page Cache, DB Cache, etc)
• All of the minify.* lines from your master.php configuration file

[bndn]

@jacobd91

I just realized that this problem happens only with the CSS Tidy minifier, but not with default Minify minifier.

I can switch back to Minify since an another bug with calc() et white spaces have been fixed a long time ago and is now included in W3 Total Cache.

mrclay/minify#560
tubalmartin/YUI-CSS-compressor-PHP-port#22

Thank you.