263104 2023-10-12 19:43:08 -0700 getComputedStyle() should return the same list than what was specified (truncation or excess) 2023-12-01 05:16:19 -0800 1 1 1 Unclassified WebKit CSS Safari 17 Unspecified Unspecified NEW https://bugs.webkit.org/show_bug.cgi?id=263115 https://bugs.webkit.org/show_bug.cgi?id=250702 BrowserCompat, InRadar, WPTImpact P2 Normal --- 261552 263051 1 karlcow webkit-unassigned emilio koivisto webkit-bug-importer oldest_to_newest 1984797 0 karlcow 2023-10-12 19:43:08 -0700 getComputedStyle(elt).* should return the specified values for coordinating list properties. .test { background-image: url(foo.ping); background-blend-mode: normal, luminosity; background-position: 0px 0px, 10px 10px; } let test = document.querySelector('.test'); window.getComputedStyle(test).backgroundBlendMode; window.getComputedStyle(test).backgroundPosition; should return (like Gecko) normal, luminosity 0px 0px, 10px 10px currently WebKit and Blink return normal 0px 0px Currently all the properties in https://searchfox.org/wubkat/rev/95664cfd77a025b5154b8fc6dd52a6cbd9c0f544/Source/WebCore/css/ComputedStyleExtractor.cpp which have the patterns auto& layers = style.backgroundLayers(); if (!layers.next()) return createConvertingToCSSValueID(layers.blendMode()); CSSValueListBuilder list; for (auto* currLayer = &layers; currLayer; currLayer = currLayer->next()) list.append(createConvertingToCSSValueID(currLayer->blendMode())); return CSSValueList::createSpaceSeparated(WTFMove(list)); will not send back the list of values as specified and will stop if the number of images and the number of associated properties is different. 1984798 1 webkit-bug-importer 2023-10-12 19:43:41 -0700 <rdar://problem/116897028> 1984799 2 karlcow 2023-10-12 19:44:53 -0700 see Comment #13 https://bugs.webkit.org/show_bug.cgi?id=261552#c13 1985025 3 karlcow 2023-10-13 16:52:19 -0700 This is happening for mask-image too.