Fix crashes with infinite lengths (part 2) (#2298)

crates/typst-library/src/layout/enum.rs

@@ -269,6 +269,7 @@ impl Layout for EnumElem {
             &cells,
             regions,
             styles,
+            self.span(),
         );
 
         Ok(layouter.layout(vt)?.fragment)

crates/typst-library/src/layout/flow.rs

@@ -29,6 +29,12 @@ impl Layout for FlowElem {
         styles: StyleChain,
         regions: Regions,
     ) -> SourceResult<Fragment> {
+        if !regions.size.x.is_finite() && regions.expand.x {
+            bail!(error!(self.span(), "cannot expand into infinite width"));
+        }
+        if !regions.size.y.is_finite() && regions.expand.y {
+            bail!(error!(self.span(), "cannot expand into infinite height"));
+        }
         let mut layouter = FlowLayouter::new(regions, styles);
 
         for mut child in &self.children() {

crates/typst-library/src/layout/grid.rs

@@ -114,6 +114,7 @@ impl Layout for GridElem {
             &cells,
             regions,
             styles,
+            self.span(),
         );
 
         // Measure the columns and layout the grid row-by-row.
@@ -161,6 +162,8 @@ pub struct GridLayouter<'a> {
     initial: Size,
     /// Frames for finished regions.
     finished: Vec<Frame>,
+    /// The span of the grid element.
+    span: Span,
 }
 
 /// The resulting sizes of columns and rows in a grid.
@@ -202,6 +205,7 @@ impl<'a> GridLayouter<'a> {
         cells: &'a [Content],
         regions: Regions<'a>,
         styles: StyleChain<'a>,
+        span: Span,
     ) -> Self {
         let mut cols = vec![];
         let mut rows = vec![];
@@ -272,6 +276,7 @@ impl<'a> GridLayouter<'a> {
             lrows: vec![],
             initial: regions.size,
             finished: vec![],
+            span,
         }
     }
 
@@ -563,6 +568,10 @@ impl<'a> GridLayouter<'a> {
         height: Abs,
         y: usize,
     ) -> SourceResult<Frame> {
+        if !height.is_finite() {
+            bail!(error!(self.span, "cannot create grid with infinite height"));
+        }
+
         let mut output = Frame::soft(Size::new(self.width, height));
         let mut pos = Point::zero();
 

crates/typst-library/src/layout/list.rs

@@ -162,6 +162,7 @@ impl Layout for ListElem {
             &cells,
             regions,
             styles,
+            self.span(),
         );
 
         Ok(layouter.layout(vt)?.fragment)

crates/typst-library/src/layout/table.rs

@@ -163,6 +163,7 @@ impl Layout for TableElem {
             &cells,
             regions,
             styles,
+            self.span(),
         );
 
         // Measure the columns and layout the grid row-by-row.

crates/typst-library/src/visualize/line.rs

@@ -75,6 +75,9 @@ impl Layout for LineElem {
         let size = start.max(start + delta).max(Size::zero());
         let target = regions.expand.select(regions.size, size);
 
+        if !target.is_finite() {
+            bail!(error!(self.span(), "cannot create line with infinite length"));
+        }
         let mut frame = Frame::soft(target);
         let shape = Geometry::Line(delta.to_point()).stroked(stroke);
         frame.push(start.to_point(), FrameItem::Shape(shape, self.span()));

crates/typst-library/src/visualize/polygon.rs

@@ -130,6 +130,9 @@ impl Layout for PolygonElem {
             .collect();
 
         let size = points.iter().fold(Point::zero(), |max, c| c.max(max)).to_size();
+        if !size.is_finite() {
+            bail!(error!(self.span(), "cannot create polygon with infinite size"));
+        }
         let mut frame = Frame::hard(size);
 
         // Only create a path if there are more than zero points.

tests/typ/bugs/layout-infinite-lengths.typ

@@ -0,0 +1,25 @@
+// Test that passing infinite lengths to drawing primitives does not crash Typst.
+
+---
+#set page(width: auto, height: auto)
+
+// Error: cannot expand into infinite width
+#layout(size => grid(columns: (size.width, size.height))[a][b][c][d])
+
+---
+#set page(width: auto, height: auto)
+
+// Error: 17-66 cannot create grid with infinite height
+#layout(size => grid(rows: (size.width, size.height))[a][b][c][d])
+
+---
+#set page(width: auto, height: auto)
+
+// Error: 17-41 cannot create line with infinite length
+#layout(size => line(length: size.width))
+
+---
+#set page(width: auto, height: auto)
+
+// Error: 17-54 cannot create polygon with infinite size
+#layout(size => polygon((0pt,0pt), (0pt, size.width)))