Ignore accent when positioning superscript

library/src/math/accent.rs

@@ -112,13 +112,14 @@ impl LayoutMath for AccentNode {
         let size = Size::new(base.width(), accent.height() + gap + base.height());
         let accent_pos = Point::with_x(base_attach - accent_attach);
         let base_pos = Point::with_y(accent.height() + gap);
+        let base_ascent = base.ascent();
         let baseline = base_pos.y + base.ascent();
 
         let mut frame = Frame::new(size);
         frame.set_baseline(baseline);
         frame.push_frame(accent_pos, accent);
         frame.push_frame(base_pos, base.to_frame(ctx));
-        ctx.push(FrameFragment::new(ctx, frame));
+        ctx.push(FrameFragment::new(ctx, frame).with_base_ascent(base_ascent));
 
         Ok(())
     }

library/src/math/attach.rs

@@ -51,12 +51,15 @@ impl LayoutMath for AttachNode {
         let base = ctx.layout_fragment(&self.base)?;
 
         ctx.style(ctx.style.for_subscript());
-        let top = self.top.as_ref().map(|node| ctx.layout_frame(node)).transpose()?;
+        let top = self.top.as_ref().map(|node| ctx.layout_fragment(node)).transpose()?;
         ctx.unstyle();
 
         ctx.style(ctx.style.for_superscript());
-        let bottom =
-            self.bottom.as_ref().map(|node| ctx.layout_frame(node)).transpose()?;
+        let bottom = self
+            .bottom
+            .as_ref()
+            .map(|node| ctx.layout_fragment(node))
+            .transpose()?;
         ctx.unstyle();
 
         let render_limits = self.base.is::<LimitsNode>()
@@ -145,8 +148,8 @@ impl LayoutMath for LimitsNode {
 fn scripts(
     ctx: &mut MathContext,
     base: MathFragment,
-    sup: Option<Frame>,
-    sub: Option<Frame>,
+    sup: Option<MathFragment>,
+    sub: Option<MathFragment>,
 ) -> SourceResult<()> {
     let sup_shift_up = if ctx.style.cramped {
         scaled!(ctx, superscript_shift_up_cramped)
@@ -166,8 +169,13 @@ fn scripts(
     let mut shift_down = Abs::zero();
 
     if let Some(sup) = &sup {
+        let ascent = match &base {
+            MathFragment::Frame(frame) => frame.base_ascent,
+            _ => base.ascent(),
+        };
+
         shift_up = sup_shift_up
-            .max(base.ascent() - sup_drop_max)
+            .max(ascent - sup_drop_max)
             .max(sup_bottom_min + sup.descent());
     }
 
@@ -222,13 +230,13 @@ fn scripts(
     if let Some(sup) = sup {
         let sup_pos =
             Point::new(sup_delta + base_width, ascent - shift_up - sup.ascent());
-        frame.push_frame(sup_pos, sup);
+        frame.push_frame(sup_pos, sup.to_frame(ctx));
     }
 
     if let Some(sub) = sub {
         let sub_pos =
             Point::new(sub_delta + base_width, ascent + shift_down - sub.ascent());
-        frame.push_frame(sub_pos, sub);
+        frame.push_frame(sub_pos, sub.to_frame(ctx));
     }
 
     ctx.push(FrameFragment::new(ctx, frame).with_class(class));
@@ -240,8 +248,8 @@ fn scripts(
 fn limits(
     ctx: &mut MathContext,
     base: MathFragment,
-    top: Option<Frame>,
-    bottom: Option<Frame>,
+    top: Option<MathFragment>,
+    bottom: Option<MathFragment>,
 ) -> SourceResult<()> {
     let upper_gap_min = scaled!(ctx, upper_limit_gap_min);
     let upper_rise_min = scaled!(ctx, upper_limit_baseline_rise_min);
@@ -275,13 +283,13 @@ fn limits(
 
     if let Some(top) = top {
         let top_pos = Point::with_x((width - top.width()) / 2.0 + delta);
-        frame.push_frame(top_pos, top);
+        frame.push_frame(top_pos, top.to_frame(ctx));
     }
 
     if let Some(bottom) = bottom {
         let bottom_pos =
             Point::new((width - bottom.width()) / 2.0 - delta, height - bottom.height());
-        frame.push_frame(bottom_pos, bottom);
+        frame.push_frame(bottom_pos, bottom.to_frame(ctx));
     }
 
     ctx.push(FrameFragment::new(ctx, frame).with_class(class));

library/src/math/fragment.rs

@@ -218,7 +218,7 @@ impl GlyphFragment {
             glyphs: vec![Glyph {
                 id: self.id.0,
                 c: self.c,
-                x_advance: Em::from_length(self.width, ctx.size),
+                x_advance: Em::from_length(self.width, self.font_size),
                 x_offset: Em::zero(),
             }],
         };
@@ -256,22 +256,25 @@ impl Debug for VariantFragment {
 #[derive(Debug, Clone)]
 pub struct FrameFragment {
     pub frame: Frame,
-    pub limits: bool,
-    pub spaced: bool,
     pub style: MathStyle,
     pub font_size: Abs,
     pub class: MathClass,
+    pub limits: bool,
+    pub spaced: bool,
+    pub base_ascent: Abs,
 }
 
 impl FrameFragment {
     pub fn new(ctx: &MathContext, frame: Frame) -> Self {
+        let base_ascent = frame.ascent();
         Self {
             frame,
-            limits: false,
-            spaced: false,
             font_size: ctx.size,
             style: ctx.style,
             class: MathClass::Normal,
+            limits: false,
+            spaced: false,
+            base_ascent,
         }
     }
 
@@ -286,6 +289,10 @@ impl FrameFragment {
     pub fn with_spaced(self, spaced: bool) -> Self {
         Self { spaced, ..self }
     }
+
+    pub fn with_base_ascent(self, base_ascent: Abs) -> Self {
+        Self { base_ascent, ..self }
+    }
 }
 
 /// Look up the italics correction for a glyph.

tests/typ/math/accent.typ

@@ -2,7 +2,7 @@
 
 ---
 // Test function call.
-$grave(a), acute(b), hat(f), tilde(§), macron(ä), diaer(a), ä, \
+$grave(a), acute(b), hat(f), tilde(§), macron(ä), diaer(a), ä \
  breve(\&), dot(!), circle(a), caron(@), arrow(Z), arrow.l(Z)$
 
 ---
@@ -17,6 +17,10 @@ $sqrt(tilde(T)) + hat(f)/hat(g)$
 // Test wide base.
 $arrow("ABC" + d), tilde(sum)$
 
+---
+// Test effect of accent on superscript.
+$A^x != hat(A)^x != hat(hat(A))^x$
+
 ---
 // Test high base.
 $ tilde(integral), tilde(integral)_a^b, tilde(integral_a^b) $