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<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - @supports parse error with the filter property when no parameter is specified"
href="https://bugs.webkit.org/show_bug.cgi?id=145874#c1">Comment # 1</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - @supports parse error with the filter property when no parameter is specified"
href="https://bugs.webkit.org/show_bug.cgi?id=145874">bug 145874</a>
from <span class="vcard"><a class="email" href="mailto:phiw2@l-c-n.com" title="Philippe Wittenbergh <phiw2@l-c-n.com>"> <span class="fn">Philippe Wittenbergh</span></a>
</span></b>
<pre>Well, after multiple readings of the relevant spec [1], I think I’m wrong – and Webkit (+ Blink) is correct.
filter: blur() or filter: grayscale(), etc without a parameter is actually valid per the mentioned spec. The spec mentions - quote (for blur()): “The lacuna value for interpolation is…”. The word ‘lacuna’ apparently refers to ‘missing parameter’. I had to ask two native English speakers for this; the relevant MDN article [2] confirms this reading (“If no parameter is provided, then a value 0 is used”). By extension @supports (filter: blur()) [or other filters] should parse as valid (prefixed atm of course).
[1] <a href="http://www.w3.org/TR/filter-effects/#FilterProperty">http://www.w3.org/TR/filter-effects/#FilterProperty</a>
[2] <a href="https://developer.mozilla.org/en-US/docs/Web/CSS/filter">https://developer.mozilla.org/en-US/docs/Web/CSS/filter</a></pre>
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