LibWeb: Clamp CSS numeric token values to float range

This matches the behavior of other browsers. We did the equivalent
change for <integer> in b86377b

We continue to store these as doubles for the extra precision.

Libraries/LibWeb/CSS/Parser/Token.h

@@ -14,6 +14,17 @@
 
 namespace Web::CSS::Parser {
 
+inline static double clamp_to_single_precision(double value)
+{
+    if (value > static_cast<double>(NumericLimits<float>::max()))
+        return static_cast<double>(NumericLimits<float>::max());
+
+    if (value < static_cast<double>(NumericLimits<float>::lowest()))
+        return static_cast<double>(NumericLimits<float>::lowest());
+
+    return value;
+}
+
 class WEB_API Token {
 public:
     enum class Type : u8 {
@@ -139,7 +150,7 @@ public:
     double number_value() const
     {
         VERIFY(m_type == Type::Number);
-        return m_number_value.value();
+        return clamp_to_single_precision(m_number_value.value());
     }
     i32 to_integer() const
     {
@@ -155,14 +166,14 @@ public:
     double dimension_value() const
     {
         VERIFY(m_type == Type::Dimension);
-        return m_number_value.value();
+        return clamp_to_single_precision(m_number_value.value());
     }
     i32 dimension_value_int() const { return m_number_value.integer_value(); }
 
     double percentage() const
     {
         VERIFY(m_type == Type::Percentage);
-        return m_number_value.value();
+        return clamp_to_single_precision(m_number_value.value());
     }
 
     Type mirror_variant() const;

Tests/LibWeb/CSSTokenizer/expected/numeric-clamping.txt

@@ -0,0 +1,12 @@
+Percentage(value=3.4028234663852886e+38, number_type=Number, source="1e39%", start=0:0, end=0:5)
+Whitespace(source="\n", start=0:5, end=1:0)
+Percentage(value=-3.4028234663852886e+38, number_type=Number, source="-1e39%", start=1:0, end=1:6)
+Whitespace(source="\n", start=1:6, end=2:0)
+Dimension(value=3.4028234663852886e+38, number_type=Number, unit="px", source="1e39px", start=2:0, end=2:6)
+Whitespace(source="\n", start=2:6, end=3:0)
+Dimension(value=-3.4028234663852886e+38, number_type=Number, unit="px", source="-1e39px", start=3:0, end=3:7)
+Whitespace(source="\n", start=3:7, end=4:0)
+Number(value=3.4028234663852886e+38, number_type=Number, source="1e39", start=4:0, end=4:4)
+Whitespace(source="\n", start=4:4, end=5:0)
+Number(value=-3.4028234663852886e+38, number_type=Number, source="-1e39", start=5:0, end=5:5)
+__EOF__(source="", start=5:5, end=5:5)

Tests/LibWeb/CSSTokenizer/input/numeric-clamping.css

@@ -0,0 +1,6 @@
+1e39%
+-1e39%
+1e39px
+-1e39px
+1e39
+-1e39