Expand the AttachElement frame so it encompasses its child center_frame (#2968)

crates/typst/src/layout/frame.rs

@@ -365,13 +365,13 @@ impl Frame {
 /// Tools for debugging.
 impl Frame {
     /// Add a full size aqua background and a red baseline for debugging.
-    pub fn debug(mut self) -> Self {
+    pub fn mark_box(mut self) -> Self {
-        self.debug_in_place();
+        self.mark_box_in_place();
         self
     }
 
-    /// Debug in place.
+    /// Debug in place. Add a full size aqua background and a red baseline for debugging.
-    pub fn debug_in_place(&mut self) {
+    pub fn mark_box_in_place(&mut self) {
         self.insert(
             0,
             Point::zero(),

crates/typst/src/math/attach.rs

@@ -243,12 +243,12 @@ fn layout_attachments(
         (base.width(), base.ascent(), base.descent());
     let base_class = base.class().unwrap_or(MathClass::Normal);
 
-    let ascent = base_ascent
+    let mut ascent = base_ascent
         .max(shift_up + measure!(tr, ascent))
         .max(shift_up + measure!(tl, ascent))
         .max(shift_up + measure!(t, height));
 
-    let descent = base_descent
+    let mut descent = base_descent
         .max(shift_down + measure!(br, descent))
         .max(shift_down + measure!(bl, descent))
         .max(shift_down + measure!(b, height));
@@ -257,23 +257,27 @@ fn layout_attachments(
     let pre_sub_width = measure!(bl, width);
     let pre_width_dif = pre_sup_width - pre_sub_width; // Could be negative.
     let pre_width_max = pre_sup_width.max(pre_sub_width);
-    let post_max_width =
+    let post_width_max =
         (sup_delta + measure!(tr, width)).max(sub_delta + measure!(br, width));
 
     let (center_frame, base_offset) = attach_top_and_bottom(ctx, base, t, b);
-    let base_pos =
-        Point::new(sup_delta + pre_width_max, ascent - base_ascent - base_offset);
     if [&tl, &bl, &tr, &br].iter().all(|&e| e.is_none()) {
         ctx.push(FrameFragment::new(ctx, center_frame).with_class(base_class));
         return Ok(());
     }
 
+    ascent.set_max(center_frame.ascent());
+    descent.set_max(center_frame.descent());
+
     let mut frame = Frame::soft(Size::new(
-        pre_width_max + base_width + post_max_width + scaled!(ctx, space_after_script),
+        pre_width_max + base_width + post_width_max + scaled!(ctx, space_after_script),
         ascent + descent,
     ));
     frame.set_baseline(ascent);
-    frame.push_frame(base_pos, center_frame);
+    frame.push_frame(
+        Point::new(sup_delta + pre_width_max, frame.ascent() - base_ascent - base_offset),
+        center_frame,
+    );
 
     if let Some(tl) = tl {
         let pos =

tests/typ/math/attach-p1.typ

@@ -49,7 +49,11 @@ $pi_1(Y), a_f(x), a^zeta (x), a^abs(b)_sqrt(c) \
 ---
 // Test associativity and scaling.
 $ 1/(V^2^3^4^5),
-  1/attach(V, tl: attach(2, tl: attach(3, tl: attach(4, tl: 5)))),
+  frac(
+    attach(
+      limits(V), br: attach(2, br: 3), b: attach(limits(2), b: 3)),
+    attach(
+      limits(V), tl: attach(2, tl: 3), t: attach(limits(2), t: 3))),
   attach(Omega,
     tl: attach(2, tl: attach(3, tl: attach(4, tl: 5))),
     tr: attach(2, tr: attach(3, tr: attach(4, tr: 5))),