Container query with font units should invalidate when font changes

https://bugs.webkit.org/show_bug.cgi?id=253940
rdar://106739736

Reviewed by Tim Nguyen.

* LayoutTests/imported/w3c/web-platform-tests/css/css-contain/container-queries/font-relative-calc-dynamic-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/css/css-contain/container-queries/font-relative-units-dynamic-expected.txt:

The remaining failures are units we don't support.

* Source/WebCore/style/StyleTreeResolver.cpp:
(WebCore::Style::styleChangeAffectsRelativeUnits):

Factor into a function.

(WebCore::Style::TreeResolver::resolveElement):
(WebCore::Style::TreeResolver::updateStateForQueryContainer):

If the container font size changes we need to evaluate all descendants in case there are container queries that use
font-relative units.

* Source/WebCore/style/StyleTreeResolver.h:

Canonical link: https://commits.webkit.org/267258@main

LayoutTests/imported/w3c/web-platform-tests/css/css-contain/container-queries/font-relative-calc-dynamic-expected.txt

@@ -1,3 +1,3 @@
 
-FAIL font-relative calc() is responsive to container font-size changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
+PASS font-relative calc() is responsive to container font-size changes
 

LayoutTests/imported/w3c/web-platform-tests/css/css-contain/container-queries/font-relative-units-dynamic-expected.txt

@@ -1,14 +1,14 @@
 
-FAIL em units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
+PASS em units respond to changes
 PASS rem units respond to changes
-FAIL ex units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
+PASS ex units respond to changes
 FAIL rex units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
-FAIL ch units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
+PASS ch units respond to changes
 FAIL cap units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
 FAIL rch units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
-FAIL lh units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
+PASS lh units respond to changes
 PASS rlh units respond to changes
-FAIL ic units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
+PASS ic units respond to changes
 FAIL ric units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
 FAIL rcap units respond to changes assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
 

Source/WebCore/style/StyleTreeResolver.cpp

@@ -211,6 +211,13 @@ auto TreeResolver::computeDescendantsToResolve(Change change, Validity validity,
     return DescendantsToResolve::None;
 };
 
+static bool styleChangeAffectsRelativeUnits(const RenderStyle& style, const RenderStyle* existingStyle)
+{
+    if (!existingStyle)
+        return true;
+    return style.computedFontSize() != existingStyle->computedFontSize();
+}
+
 auto TreeResolver::resolveElement(Element& element, const RenderStyle* existingStyle, ResolutionType resolutionType) -> std::pair<ElementUpdate, DescendantsToResolve>
 {
     if (m_didSeePendingStylesheet && !element.renderOrDisplayContentsStyle() && !m_document.isIgnoringPendingStylesheets()) {
@@ -233,7 +240,7 @@ auto TreeResolver::resolveElement(Element& element, const RenderStyle* existingS
     auto descendantsToResolve = computeDescendantsToResolve(update.change, element.styleValidity(), parent().descendantsToResolve);
 
     if (&element == m_document.documentElement()) {
-        if (!existingStyle || existingStyle->computedFontSize() != update.style->computedFontSize()) {
+        if (styleChangeAffectsRelativeUnits(*update.style, existingStyle)) {
             // "rem" units are relative to the document element's font size so we need to recompute everything.
             scope().resolver->invalidateMatchedDeclarationsCache();
             descendantsToResolve = DescendantsToResolve::All;
@@ -858,7 +865,6 @@ void TreeResolver::resolveComposedTree()
 
         auto change = Change::None;
         auto descendantsToResolve = DescendantsToResolve::None;
-        auto previousContainerType = style ? style->containerType() : ContainerType::Normal;
 
         auto resolutionType = determineResolutionType(element, style, parent.descendantsToResolve, parent.change);
         if (resolutionType) {
@@ -889,7 +895,7 @@ void TreeResolver::resolveComposedTree()
         if (!style)
             resetStyleForNonRenderedDescendants(element);
 
-        auto queryContainerAction = updateStateForQueryContainer(element, style, previousContainerType, change, descendantsToResolve);
+        auto queryContainerAction = updateStateForQueryContainer(element, style, change, descendantsToResolve);
 
         bool shouldIterateChildren = [&] {
             // display::none, no need to resolve descendants.
@@ -937,7 +943,7 @@ const RenderStyle* TreeResolver::existingStyle(const Element& element)
     return style;
 }
 
-auto TreeResolver::updateStateForQueryContainer(Element& element, const RenderStyle* style, ContainerType previousContainerType, Change& change, DescendantsToResolve& descendantsToResolve) -> QueryContainerAction
+auto TreeResolver::updateStateForQueryContainer(Element& element, const RenderStyle* style, Change& change, DescendantsToResolve& descendantsToResolve) -> QueryContainerAction
 {
     if (!style)
         return QueryContainerAction::None;
@@ -955,7 +961,11 @@ auto TreeResolver::updateStateForQueryContainer(Element& element, const RenderSt
         return QueryContainerAction::Continue;
     }
 
-    if (style->containerType() != ContainerType::Normal || previousContainerType != ContainerType::Normal) {
+    auto* existingStyle = element.renderOrDisplayContentsStyle();
+    if (style->containerType() != ContainerType::Normal || (existingStyle && existingStyle->containerType() != ContainerType::Normal)) {
+        // If any of the queries use font-size relative units then a font size change may affect their evaluation.
+        if (styleChangeAffectsRelativeUnits(*style, existingStyle))
+            descendantsToResolve = DescendantsToResolve::All;
         m_queryContainerStates.add(element, QueryContainerState { change, descendantsToResolve });
         m_hasUnresolvedQueryContainers = true;
         return QueryContainerAction::Resolve;

Source/WebCore/style/StyleTreeResolver.h

@@ -70,7 +70,7 @@ class TreeResolver {
     enum class QueryContainerAction : uint8_t { None, Resolve, Continue };
     enum class DescendantsToResolve : uint8_t { None, ChildrenWithExplicitInherit, Children, All };
 
-    QueryContainerAction updateStateForQueryContainer(Element&, const RenderStyle*, ContainerType previousContainerType, Change&, DescendantsToResolve&);
+    QueryContainerAction updateStateForQueryContainer(Element&, const RenderStyle*, Change&, DescendantsToResolve&);
 
     std::pair<ElementUpdate, DescendantsToResolve> resolveElement(Element&, const RenderStyle* existingStyle, ResolutionType);