Bug 1682607 - Normalize NaN in some other font-related lengths etc. r=jfkthame,layout-reviewers

Depends on D104563 Differential Revision: https://phabricator.services.mozilla.com/D104565
2021-02-10 15:30:40 +00:00 · 2021-02-10 15:30:40 +00:00 · 1691b8a61c
--- a/servo/components/style/values/specified/font.rs
+++ b/servo/components/style/values/specified/font.rs
@ -925,7 +925,7 @@ impl FontSize {
                // If the parent font was keyword-derived, this is too.
                // Tack the % onto the factor
                info = compose_keyword(pc.0);
-                base_size.resolve(context) * pc.0
+                (base_size.resolve(context) * pc.0).normalized()
            },
            FontSize::Length(LengthPercentage::Calc(ref calc)) => {
                let calc = calc.to_computed_value_zoomed(context, base_size);
--- a/servo/components/style/values/specified/length.rs
+++ b/servo/components/style/values/specified/length.rs
@ -135,7 +135,7 @@ impl FontRelativeLength {
        base_size: FontBaseSize,
    ) -> computed::Length {
        let (reference_size, length) = self.reference_font_size_and_length(context, base_size);
-        reference_size * length
+        (reference_size * length).normalized()
    }

    /// Return reference font size.
--- a/testing/web-platform/tests/css/css-fonts/infinite-size-crash.html
+++ b/testing/web-platform/tests/css/css-fonts/infinite-size-crash.html
@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <style>
+        CITE::first-letter {
+            font-size: 0%;
+            margin-inline-start: 2682182284.200815ch
+        }
+
+        * {
+            font-size: 4294967295% !important;
+        }
+    </style>
+</head>
+<del>
+    <button>
+        <cite></cite>
+    </button>
+</del>
+</html>