LibWeb: Ignore CSS properties with other people's vendor prefixes

This removes some `Property '-webkit-foo' has no value.` log spam. :^)

2 files changed, 22 insertions, 5 deletions

diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
index 0fe7343138..afb454a57c 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
@@ -1312,12 +1312,16 @@ Optional<StyleProperty> Parser::convert_to_style_property(StyleDeclarationRule&
 
     auto& property_name = declaration.m_name;
     auto property_id = property_id_from_string(property_name);
-    if (property_id == PropertyID::Invalid && property_name.starts_with("--"))
-        property_id = PropertyID::Custom;
 
-    if (property_id == PropertyID::Invalid && !property_name.starts_with("-")) {
-        dbgln("Parser::convert_to_style_property(): Unrecognized property '{}'", property_name);
-        return {};
+    if (property_id == PropertyID::Invalid) {
+        if (property_name.starts_with("--")) {
+            property_id = PropertyID::Custom;
+        } else if (has_ignored_vendor_prefix(property_name)) {
+            return {};
+        } else if (!property_name.starts_with("-")) {
+            dbgln("Parser::convert_to_style_property(): Unrecognized property '{}'", property_name);
+            return {};
+        }
     }
 
     auto value_token_stream = TokenStream(declaration.m_values);
@@ -3475,6 +3479,17 @@ OwnPtr<CalculatedStyleValue::CalcSum> Parser::parse_calc_sum(ParsingContext cons
     return make<CalculatedStyleValue::CalcSum>(parsed_calc_product.release_nonnull(), move(additional));
 }
 
+bool Parser::has_ignored_vendor_prefix(StringView const& string)
+{
+    if (!string.starts_with('-'))
+        return false;
+    if (string.starts_with("--"))
+        return false;
+    if (string.starts_with("-libweb-"))
+        return false;
+    return true;
+}
+
 }
 
 namespace Web {
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Parser.h b/Userland/Libraries/LibWeb/CSS/Parser/Parser.h
index 7b9c566fbc..66800c7cc1 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Parser.h
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Parser.h
@@ -216,6 +216,8 @@ private:
     Optional<Selector::Combinator> parse_selector_combinator(TokenStream<StyleComponentValueRule>&);
     Result<Selector::SimpleSelector, SelectorParsingResult> parse_simple_selector(TokenStream<StyleComponentValueRule>&);
 
+    static bool has_ignored_vendor_prefix(StringView const&);
+
     ParsingContext m_context;
 
     Tokenizer m_tokenizer;