Revert "LibWeb/CSS: Keep invalid parts of <forgiving-selector-list>s around"

This reverts commit 698dd600f2.

This caused multiple tests to crash on macOS:
https://github.com/LadybirdBrowser/ladybird/pull/2317#issuecomment-2474725826

Libraries/LibWeb/CSS/Parser/SelectorParsing.cpp

@@ -60,29 +60,6 @@ Optional<Selector::PseudoElement> Parser::parse_as_pseudo_element_selector()
     return simple_selector.pseudo_element();
 }
 
-static NonnullRefPtr<Selector> create_invalid_selector(Vector<ComponentValue> component_values)
-{
-    // Trim leading and trailing whitespace
-    while (!component_values.is_empty() && component_values.first().is(Token::Type::Whitespace)) {
-        component_values.take_first();
-    }
-    while (!component_values.is_empty() && component_values.last().is(Token::Type::Whitespace)) {
-        component_values.take_last();
-    }
-
-    Selector::SimpleSelector simple {
-        .type = Selector::SimpleSelector::Type::Invalid,
-        .value = Selector::SimpleSelector::Invalid {
-            .component_values = move(component_values),
-        }
-    };
-    Selector::CompoundSelector compound {
-        .combinator = Selector::Combinator::None,
-        .simple_selectors = { move(simple) }
-    };
-    return Selector::create({ move(compound) });
-}
-
 template<typename T>
 Parser::ParseErrorOr<SelectorList> Parser::parse_a_selector_list(TokenStream<T>& tokens, SelectorType mode, SelectorParsingMode parsing_mode)
 {
@@ -93,11 +70,8 @@ Parser::ParseErrorOr<SelectorList> Parser::parse_a_selector_list(TokenStream<T>&
         auto stream = TokenStream(selector_parts);
         auto selector = parse_complex_selector(stream, mode);
         if (selector.is_error()) {
-            if (parsing_mode == SelectorParsingMode::Forgiving) {
-                // Keep the invalid selector around for serialization and nesting
-                selectors.append(create_invalid_selector(move(selector_parts)));
+            if (parsing_mode == SelectorParsingMode::Forgiving)
                 continue;
-            }
             return selector.error();
         }
         selectors.append(selector.release_value());

Libraries/LibWeb/CSS/Selector.cpp

@@ -11,28 +11,6 @@
 
 namespace Web::CSS {
 
-static bool component_value_contains_nesting_selector(Parser::ComponentValue const& component_value)
-{
-    if (component_value.is_delim('&'))
-        return true;
-
-    if (component_value.is_block()) {
-        for (auto const& child_value : component_value.block().value) {
-            if (component_value_contains_nesting_selector(child_value))
-                return true;
-        }
-    }
-
-    if (component_value.is_function()) {
-        for (auto const& child_value : component_value.function().value) {
-            if (component_value_contains_nesting_selector(child_value))
-                return true;
-        }
-    }
-
-    return false;
-}
-
 Selector::Selector(Vector<CompoundSelector>&& compound_selectors)
     : m_compound_selectors(move(compound_selectors))
 {
@@ -66,17 +44,6 @@ Selector::Selector(Vector<CompoundSelector>&& compound_selectors)
                 if (m_contains_the_nesting_selector)
                     break;
             }
-            if (simple_selector.type == SimpleSelector::Type::Invalid) {
-                auto& invalid = simple_selector.value.get<SimpleSelector::Invalid>();
-                for (auto& item : invalid.component_values) {
-                    if (component_value_contains_nesting_selector(item)) {
-                        m_contains_the_nesting_selector = true;
-                        break;
-                    }
-                }
-                if (m_contains_the_nesting_selector)
-                    break;
-            }
         }
         if (m_contains_the_nesting_selector)
             break;
@@ -217,9 +184,6 @@ u32 Selector::specificity() const
                 // The parented case is handled by replacing & with :is().
                 // So if we got here, the specificity is 0.
                 break;
-            case SimpleSelector::Type::Invalid:
-                // Ignore invalid selectors
-                break;
             }
         }
     }
@@ -396,12 +360,6 @@ String Selector::SimpleSelector::serialize() const
         // AD-HOC: Not in spec yet.
         s.append('&');
         break;
-    case Type::Invalid:
-        // AD-HOC: We're not told how to do these. Just serialize their component values.
-        auto invalid = value.get<Invalid>();
-        for (auto const& component_value : invalid.component_values)
-            s.append(component_value.to_string());
-        break;
     }
     return MUST(s.to_string());
 }
@@ -644,7 +602,6 @@ Selector::SimpleSelector Selector::SimpleSelector::absolutized(Selector::SimpleS
     case Type::Class:
     case Type::Attribute:
     case Type::PseudoElement:
-    case Type::Invalid:
         // Everything else isn't affected
         return *this;
     }

Libraries/LibWeb/CSS/Selector.h

@@ -12,7 +12,6 @@
 #include <AK/String.h>
 #include <AK/Vector.h>
 #include <LibWeb/CSS/Keyword.h>
-#include <LibWeb/CSS/Parser/ComponentValue.h>
 #include <LibWeb/CSS/PseudoClass.h>
 
 namespace Web::CSS {
@@ -93,7 +92,6 @@ public:
             PseudoClass,
             PseudoElement,
             Nesting,
-            Invalid,
         };
 
         struct ANPlusBPattern {
@@ -197,12 +195,8 @@ public:
             CaseType case_type;
         };
 
-        struct Invalid {
-            Vector<Parser::ComponentValue> component_values;
-        };
-
         Type type;
-        Variant<Empty, Attribute, PseudoClassSelector, PseudoElement, Name, QualifiedName, Invalid> value {};
+        Variant<Empty, Attribute, PseudoClassSelector, PseudoElement, Name, QualifiedName> value {};
 
         Attribute const& attribute() const { return value.get<Attribute>(); }
         Attribute& attribute() { return value.get<Attribute>(); }

Libraries/LibWeb/CSS/SelectorEngine.cpp

@@ -764,9 +764,6 @@ static inline bool matches(CSS::Selector::SimpleSelector const& component, Optio
         // :is() is handled already, by us replacing it with :is() directly, so if we
         // got here, it's :scope.
         return matches_pseudo_class(CSS::Selector::SimpleSelector::PseudoClassSelector { .type = CSS::PseudoClass::Scope }, style_sheet_for_rule, element, shadow_host, scope, selector_kind);
-    case CSS::Selector::SimpleSelector::Type::Invalid:
-        // Invalid selectors never match
-        return false;
     }
     VERIFY_NOT_REACHED();
 }

Libraries/LibWeb/Dump.cpp

@@ -506,9 +506,6 @@ void dump_selector(StringBuilder& builder, CSS::Selector const& selector, int in
             case CSS::Selector::SimpleSelector::Type::Nesting:
                 type_description = "Nesting";
                 break;
-            case CSS::Selector::SimpleSelector::Type::Invalid:
-                type_description = "INVALID";
-                break;
             }
 
             builder.appendff("{}:", type_description);
@@ -602,14 +599,6 @@ void dump_selector(StringBuilder& builder, CSS::Selector const& selector, int in
                 builder.appendff(", value='{}']", attribute.value);
             }
 
-            if (simple_selector.type == CSS::Selector::SimpleSelector::Type::Invalid) {
-                auto invalid = simple_selector.value.get<CSS::Selector::SimpleSelector::Invalid>();
-                builder.append(" '"sv);
-                for (auto const& component_value : invalid.component_values)
-                    builder.append(component_value.to_string());
-                builder.append("'"sv);
-            }
-
             if (i != relative_selector.simple_selectors.size() - 1)
                 builder.append(", "sv);
         }

Tests/LibWeb/TestConfig.ini

@@ -61,6 +61,7 @@ Text/input/wpt-import/css/css-flexbox/flex-item-compressible-001.html
 Ref/input/wpt-import/css/css-nesting/has-nesting.html
 Ref/input/wpt-import/css/css-nesting/host-nesting-003.html
 Ref/input/wpt-import/css/css-nesting/host-nesting-004.html
+Ref/input/wpt-import/css/css-nesting/nest-containing-forgiving.html
 Ref/input/wpt-import/css/CSS2/floats/floats-wrap-top-below-bfc-002r.xht
 Ref/input/wpt-import/css/CSS2/floats/float-nowrap-3.html
 Ref/input/wpt-import/css/CSS2/floats/overflow-scroll-float-paint-order.html

Tests/LibWeb/Text/expected/css/serialize-invalid-forgiving-selectors.txt

@@ -1,2 +0,0 @@
-:is(hello, !?) -> :is(hello, !?)
-:is(what, :fake(:imaginary), really) -> :is(what, :fake(:imaginary), really)

Tests/LibWeb/Text/input/css/serialize-invalid-forgiving-selectors.html

@@ -1,17 +0,0 @@
-<!DOCTYPE html>
-<style id="style"></style>
-<script src="../include.js"></script>
-<script>
-    test(() => {
-        const selectors = [
-            ":is(hello, !?)",
-            ":is(what, :fake(:imaginary), really)",
-        ];
-        let stylesheet = document.styleSheets[0];
-        for (let selector of selectors) {
-            stylesheet.insertRule(`${selector} { }`);
-            println(`${selector} -> ${stylesheet.cssRules[0].selectorText}`);
-            stylesheet.deleteRule(0);
-        }
-    });
-</script>