REGRESSION: (264863@main) Fix regression in CSSCalcValue

[chirags27]

db8fe90

REGRESSION: (264863@main) Fix regression in CSSCalcValue
https://bugs.webkit.org/show_bug.cgi?id=258684
rdar://111512503

Reviewed by Antti Koivisto.

This change fixes a regression introduced in rdar://109503971 where we
now create a step operation with no children. This makes sense for
CalcOperator::Round, but not for CalcOperator::Mod and CalcOperator::Rem

* LayoutTests/fast/css/css-calc-rem-no-children-crash-expected.txt: Added.
* LayoutTests/fast/css/css-calc-rem-no-children-crash.html: Added.
* Source/WebCore/css/calc/CSSCalcValue.cpp:
(WebCore::createCSS):

Canonical link: https://commits.webkit.org/265667@main

56fc962

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 5e35e16)

Details

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress
	✅ 🛠 watch
	✅ 🛠 watch-sim

[chirags27]

This fixes a regression from #14208

[nmoucht]

LGTM

[smfr]

Fix regression in CSSCalcValue

The title says it's a regression, so should give the revision at which it regressed (like REGRESSION 123@main:).

[webkit-early-warning-system]

EWS run on current version of this PR (hash 56fc962)

Details

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 265667@main (db8fe90): https://commits.webkit.org/265667@main

Reviewed commits have been landed. Closing PR #15414 and removing active labels.