From 85a269b609981326e0a0360bd00f0c1007f4a818 Mon Sep 17 00:00:00 2001
From: webdevtodayjason <115739170+webdevtodayjason@users.noreply.github.com>
Date: Mon, 12 Oct 2026 18:03:15 +0000
Subject: [PATCH] SVG: non-finite viewBox and nested sizes no longer panic the
 importer

---
 crates/svg/src/lib.rs   |  8 ++++----
 crates/svg/src/tests.rs | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/crates/svg/src/lib.rs b/crates/svg/src/lib.rs
index 75985fbd1..2497294ed 100644
--- a/crates/svg/src/lib.rs
+++ b/crates/svg/src/lib.rs
@@ -789,8 +789,8 @@ impl<'a, 'i> Parser<'a, 'i> {
                 // Nested viewport.
                 let x = self.attr_len(n, "x", 'x', &st);
                 let y = self.attr_len(n, "y", 'y', &st);
-                let w = n.attribute("width").and_then(|v| self.length(v, 'x', st.font_size)).unwrap_or(self.vw);
-                let h = n.attribute("height").and_then(|v| self.length(v, 'y', st.font_size)).unwrap_or(self.vh);
+                let w = n.attribute("width").and_then(|v| self.length(v, 'x', st.font_size)).filter(|v| v.is_finite()).unwrap_or(self.vw);
+                let h = n.attribute("height").and_then(|v| self.length(v, 'y', st.font_size)).filter(|v| v.is_finite()).unwrap_or(self.vh);
                 let vb = viewbox_transform(n, w, h);
                 let mut children = vec![];
                 let saved = (self.vw, self.vh);
@@ -926,7 +926,7 @@ impl<'a, 'i> Parser<'a, 'i> {
             }
             "rect" => {
                 let (w, h) = (l("width", 'x'), l("height", 'y'));
-                if w <= 0.0 || h <= 0.0 {
+                if !(w > 0.0 && h > 0.0) {
                     return None;
                 }
                 let rx_a = n.attribute("rx").and_then(|v| self.length(v, 'x', st.font_size));
@@ -981,7 +981,7 @@ impl<'a, 'i> Parser<'a, 'i> {
 
 fn viewbox(n: roxmltree::Node) -> Option<([f64; 2], f64, f64)> {
     let v = pathdata::numbers(n.attribute("viewBox")?);
-    (v.len() == 4 && v[2] > 0.0 && v[3] > 0.0).then(|| ([v[0], v[1]], v[2], v[3]))
+    (v.len() == 4 && v.iter().all(|x| x.is_finite()) && v[2] > 0.0 && v[3] > 0.0).then(|| ([v[0], v[1]], v[2], v[3]))
 }
 
 /// The viewBox → viewport transform (`preserveAspectRatio`, default `xMidYMid meet`).
diff --git a/crates/svg/src/tests.rs b/crates/svg/src/tests.rs
index 3553205d8..243b87ff0 100644
--- a/crates/svg/src/tests.rs
+++ b/crates/svg/src/tests.rs
@@ -119,6 +119,45 @@ fn nested_svg_percentages_use_the_nearest_viewport() {
     assert_eq!(px(&img, 55, 65)[3], 0.0);
 }
 
+#[test]
+fn non_finite_viewboxes_do_not_panic_or_produce_nan_geometry() {
+    for attrs in ["viewBox=\"0 0 1e400 100\"", "viewBox=\"0 0 100 1e400\"", "viewBox=\"-1e400 0 100 100\""] {
+        for shape in ["<rect width=\"0%\" height=\"50%\"/>", "<circle r=\"0%\"/>"] {
+            let svg = format!(r#"<svg xmlns="http://www.w3.org/2000/svg" {attrs}>{shape}<rect width="50%" height="50%"/></svg>"#);
+            let d = parse(svg.as_bytes()).unwrap();
+            assert_eq!((d.width, d.height), (300.0, 150.0));
+            let shapes = d.flatten();
+            assert_eq!(shapes.len(), 1);
+            assert!(matches!(shapes[0].2.geom, Geom::Rect { x, y, w, h, rx, ry }
+                if [x, y, w, h, rx, ry].iter().all(|v| v.is_finite()) && w == 150.0 && h == 75.0));
+            assert!(shapes[0].0.as_coeffs().iter().all(|v| v.is_finite()));
+        }
+    }
+}
+
+#[test]
+fn non_finite_nested_viewports_do_not_panic_or_produce_nan_geometry() {
+    for attrs in ["width=\"1e400\" height=\"10\"", "width=\"10\" height=\"1e400\""] {
+        for shape in ["<rect width=\"0%\" height=\"50%\"/>", "<circle r=\"0%\"/>"] {
+            let svg = format!(r#"<svg xmlns="http://www.w3.org/2000/svg"><svg {attrs}>{shape}<rect width="50%" height="50%"/></svg></svg>"#);
+            let d = parse(svg.as_bytes()).unwrap();
+            let shapes = d.flatten();
+            assert_eq!(shapes.len(), 1);
+            assert!(matches!(shapes[0].2.geom, Geom::Rect { x, y, w, h, rx, ry }
+                if [x, y, w, h, rx, ry].iter().all(|v| v.is_finite()) && w > 0.0 && h > 0.0));
+            assert!(shapes[0].0.as_coeffs().iter().all(|v| v.is_finite()));
+        }
+    }
+}
+
+#[test]
+fn zero_size_nested_viewport_draws_nothing() {
+    for attrs in ["width=\"0\" height=\"10\"", "width=\"10\" height=\"0\""] {
+        let svg = format!(r#"<svg xmlns="http://www.w3.org/2000/svg"><svg {attrs}><rect width="50%" height="50%"/></svg></svg>"#);
+        assert!(parse(svg.as_bytes()).unwrap().flatten().is_empty(), "{attrs}");
+    }
+}
+
 #[test]
 fn malformed_input() {
     assert!(parse(b"<html/>").is_err());