From d13617ed9b9dd95376b8d068b85513cba8b1b702 Mon Sep 17 00:00:00 2001
From: PgBiel <9021226+PgBiel@users.noreply.github.com>
Date: Sat, 21 Jun 2025 23:36:31 -0300
Subject: [PATCH] skip layout of redundant gutter at the top of footer

---
 crates/typst-layout/src/grid/layouter.rs     |   2 +-
 crates/typst-layout/src/grid/repeated.rs     |  20 ++++++++++++++++---
 tests/ref/grid-footer-gutter-short-lived.png | Bin 0 -> 321 bytes
 tests/suite/layout/grid/footers.typ          |  14 +++++++++++++
 4 files changed, 32 insertions(+), 4 deletions(-)
 create mode 100644 tests/ref/grid-footer-gutter-short-lived.png

diff --git a/crates/typst-layout/src/grid/layouter.rs b/crates/typst-layout/src/grid/layouter.rs
index fd846b6e9..8e810e32b 100644
--- a/crates/typst-layout/src/grid/layouter.rs
+++ b/crates/typst-layout/src/grid/layouter.rs
@@ -232,7 +232,7 @@ pub(super) enum Row {
 
 impl Row {
     /// Returns the `y` index of this row.
-    fn index(&self) -> usize {
+    pub(super) fn index(&self) -> usize {
         match self {
             Self::Frame(_, y, _) => *y,
             Self::Fr(_, y, _) => *y,
diff --git a/crates/typst-layout/src/grid/repeated.rs b/crates/typst-layout/src/grid/repeated.rs
index 86506df79..6a76cb71a 100644
--- a/crates/typst-layout/src/grid/repeated.rs
+++ b/crates/typst-layout/src/grid/repeated.rs
@@ -679,9 +679,23 @@ impl<'a> GridLayouter<'a> {
         let footer_len = footer.range.end - footer.range.start;
         self.unbreakable_rows_left += footer_len;
 
-        // TODO(subfooters): also consider omitted gutter before the footer
-        // when there is a header right before it taking it.
-        for y in footer.range.clone() {
+        let footer_start = if self.grid.is_gutter_track(footer.range.start)
+            && self
+                .current
+                .lrows
+                .last()
+                .is_none_or(|r| self.grid.is_gutter_track(r.index()))
+        {
+            // Skip gutter at the top of footer if there's already a gutter
+            // from a repeated header right before it in the current region.
+            // Normally, that shouldn't happen as it indicates we have a widow,
+            // but we can't fully prevent widows anyway.
+            footer.range.start + 1
+        } else {
+            footer.range.start
+        };
+
+        for y in footer_start..footer.range.end {
             self.layout_row_with_state(
                 y,
                 engine,
diff --git a/tests/ref/grid-footer-gutter-short-lived.png b/tests/ref/grid-footer-gutter-short-lived.png
new file mode 100644
index 0000000000000000000000000000000000000000..2eb74a8615bcd06de1de819fadd855cb4622a9a4
GIT binary patch
literal 321
zcmV-H0lxl;P)<h;3K|Lk000e1NJLTq004LZ003?X00000$$*H600039Nkl<Zc-rmQ
z%?bfg7>98e>n@aRCL)m{Wv_fhW@e!VXY#or8&aaAB<yEtbZp$gc`?s_WBFUm%yD{R
zq0nN$z`%b5pB$y<9!<keLFtt`reUStKNBxX@W#E%zz4f70~efhl%8=f+t<stO~aSr
zLT_|74euL$z2?p|?3NdL)vmzHwU#<S5>l`=7|Xz!(2{}6Y8t7N%d+({Ez|IAw$htl
zxn%+a{~9bco-r^mF!6=>LVO{<5MM;%3n!NW_~8#^;9~HUftQsn@rC#T3=B+s;pGAb
zCcY3~h%dw!;tTP`w}s+MkP`Zi{iF<>3x&SpnimfzUR3@TKNkV+T)@D<Uk<+jMJWU>
TiOG=>00000NkvXXu0mjf{<w>4

literal 0
HcmV?d00001

diff --git a/tests/suite/layout/grid/footers.typ b/tests/suite/layout/grid/footers.typ
index 286928b85..b79841219 100644
--- a/tests/suite/layout/grid/footers.typ
+++ b/tests/suite/layout/grid/footers.typ
@@ -41,6 +41,20 @@
   )
 )
 
+--- grid-footer-gutter-short-lived ---
+// Gutter, no repetition, short-lived
+#set page(height: 6em)
+#set text(6pt)
+#set table(inset: 2pt, stroke: 0.5pt)
+#table(
+  gutter: 2pt,
+  align: center + horizon,
+  table.header([a]),
+  table.footer([b]),
+  table.footer([c]),
+  [d],
+)
+
 --- grid-cell-override-in-header-and-footer ---
 #table(
   table.header(table.cell(stroke: red)[Hello]),