Fix inline math formula frame size

src/eval/raw.rs

@@ -43,6 +43,12 @@ impl RawAlign {
     }
 }
 
+impl From<Align> for RawAlign {
+    fn from(align: Align) -> Self {
+        Self::Specific(align)
+    }
+}
+
 impl Debug for RawAlign {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         match self {

src/library/math/mod.rs

@@ -56,7 +56,7 @@ impl Show for MathNode {
         };
 
         Ok(if self.display {
-            Content::block(node)
+            Content::block(node.pack().aligned(Spec::with_x(Some(Align::Center.into()))))
         } else {
             Content::inline(node)
         })

src/library/math/rex.rs

@@ -58,19 +58,24 @@ impl Layout for RexNode {
         // Determine the metrics.
         let (x0, y0, x1, y1) = renderer.size(&layout);
         let width = Length::pt(x1 - x0);
-        let height = Length::pt(y1 - y0);
-        let size = Size::new(width, height);
-        let baseline = Length::pt(y1);
+        let mut top = Length::pt(y1);
+        let mut bottom = Length::pt(-y0);
+        if !self.display {
+            let metrics = face.metrics();
+            top = styles.get(TextNode::TOP_EDGE).resolve(styles, metrics);
+            bottom = -styles.get(TextNode::BOTTOM_EDGE).resolve(styles, metrics);
+        };
 
         // Prepare a frame rendering backend.
+        let size = Size::new(width, top + bottom);
         let mut backend = FrameBackend {
             frame: {
                 let mut frame = Frame::new(size);
-                frame.set_baseline(baseline);
+                frame.set_baseline(top);
                 frame.apply_role(Role::Formula);
                 frame
             },
-            baseline,
+            baseline: top,
             face_id,
             fill: styles.get(TextNode::FILL),
             lang: styles.get(TextNode::LANG),

src/model/layout.rs

@@ -19,10 +19,9 @@ use crate::Context;
 
 /// A node that can be layouted into a sequence of regions.
 ///
-/// Layout return one frame per used region alongside constraints that define
-/// whether the result is reusable in other regions.
+/// Layouting return one frame per used region.
 pub trait Layout: 'static {
-    /// Layout this node into the given regions, producing constrained frames.
+    /// Layout this node into the given regions, producing frames.
     fn layout(
         &self,
         ctx: &mut Context,