From 5b431c66308f747b5dc8b8711f18a1ab53d61e62 Mon Sep 17 00:00:00 2001
From: Guillaume Ayoub <guillaume@courtbouillon.org>
Date: Wed, 4 Mar 2026 18:21:53 +0100
Subject: [PATCH 1/2] Avoid endless loops in grids

Fix #2691.
---
 tests/layout/test_grid.py | 37 +++++++++++++++++++++++++++++++++++++
 weasyprint/layout/grid.py | 10 ++++++----
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/tests/layout/test_grid.py b/tests/layout/test_grid.py
index 8ff75908f..a4bff2f48 100644
--- a/tests/layout/test_grid.py
+++ b/tests/layout/test_grid.py
@@ -1863,3 +1863,40 @@ def test_grid_in_flex_after_full_height():
     grid, = flex.children
     grid_item, = grid.children
     assert not grid_item.children
+
+
+@assert_no_logs
+def test_grid_in_columns():
+    # Regression test for #2691.
+    page1, page2, = render_pages('''
+      <style>
+        @page { size: 12cm }
+        section { height: 10cm }
+      </style>
+      <div style="columns: 2">
+        <div style="display: grid">
+          <div>
+            <section></section>
+            <section></section>
+            <section></section>
+          </div>
+        </div>
+      </div>
+    ''')
+    html, = page1.children
+    body, = html.children
+    div, = body.children
+    column1, column2 = div.children
+    grid, = column1.children
+    assert len(grid.children) == 1
+    grid, = column2.children
+    assert len(grid.children) == 1
+
+    html, = page2.children
+    body, = html.children
+    div, = body.children
+    column1, column2 = div.children
+    grid, = column1.children
+    assert len(grid.children) == 1
+    grid, = column2.children
+    assert len(grid.children) == 0
diff --git a/weasyprint/layout/grid.py b/weasyprint/layout/grid.py
index b5a041962..d371cf5a7 100644
--- a/weasyprint/layout/grid.py
+++ b/weasyprint/layout/grid.py
@@ -1315,7 +1315,6 @@ def _add_page_children(max_row=inf):
             context, child, bottom_space, child_skip_stack, parent,
             page_is_empty, absolute_boxes, fixed_boxes)[:3]
         if new_child:
-            page_is_empty = False
             broken_child = False
             span = _get_span(child.style['grid_row_start'])
             if child_resume_at:
@@ -1337,7 +1336,10 @@ def _add_page_children(max_row=inf):
                 # last child.
                 assert isinstance(new_child, boxes.ParentBox)
                 previous_skip_child = max(child_skip_stack) if child_skip_stack else 0
-                resume_at[y][i] = {previous_skip_child + len(new_child.children): None}
+                if not page_is_empty:
+                    resume_at[y][i] = {
+                        previous_skip_child + len(new_child.children): None}
+            page_is_empty = False
         else:
             if resume_at is None:
                 resume_at = {}
@@ -1418,10 +1420,10 @@ def _add_page_children(max_row=inf):
             broken_child = y + span >= next_page_last_row + 1
             if broken_child and child.style['box_decoration_break'] != 'clone':
                 child.remove_decoration(start=False, end=True)
-            child.height = (
+            child.height = max(0, (
                 context.page_bottom - bottom_space - child.position_y -
                 child.margin_top - child.border_top_width - child.padding_top -
-                child.margin_bottom - child.border_bottom_width - child.padding_bottom)
+                child.margin_bottom - child.border_bottom_width - child.padding_bottom))
             if broken_child:
                 # Child not fully drawn, keep advancement.
                 advancements[x, y] = child.margin_height()

From d74fb34e466c2906b8cb840d358f0bfd606417f7 Mon Sep 17 00:00:00 2001
From: Guillaume Ayoub <guillaume@courtbouillon.org>
Date: Fri, 6 Mar 2026 15:47:27 +0100
Subject: [PATCH 2/2] Add failing test for #2695

---
 tests/layout/test_grid.py | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tests/layout/test_grid.py b/tests/layout/test_grid.py
index a4bff2f48..cd1297f32 100644
--- a/tests/layout/test_grid.py
+++ b/tests/layout/test_grid.py
@@ -2,6 +2,8 @@
 
 from math import isclose
 
+import pytest
+
 from ..testing_utils import assert_no_logs, render_pages
 
 
@@ -1900,3 +1902,40 @@ def test_grid_in_columns():
     assert len(grid.children) == 1
     grid, = column2.children
     assert len(grid.children) == 0
+
+
+@pytest.mark.xfail
+@assert_no_logs
+def test_grid_in_columns_with_break():
+    # Regression test for #2695.
+    page1, page2, = render_pages('''
+      <style>
+        @page { size: 12px }
+        section { height: 4px }
+      </style>
+      <div style="columns: 1">
+        <div style="display: grid; margin-top: 6px">
+          <div>
+            <section></section>
+            <section></section>
+            <section></section>
+          </div>
+        </div>
+      </div>
+    ''')
+    html, = page1.children
+    body, = html.children
+    div, = body.children
+    column1, = div.children
+    grid, = column1.children
+    section1, = grid.children
+    assert section1.position_y == 6
+
+    html, = page2.children
+    body, = html.children
+    div, = body.children
+    column1, = div.children
+    grid, = column1.children
+    section2, section3 = grid.children
+    assert section2.position_y == 0
+    assert section3.position_y == 4