Don’t try to break tables after the header or before the footer

Related to #1027.

weasyprint/layout/blocks.py

@@ -800,6 +800,11 @@ def find_earlier_page_break(children, absolute_boxes, fixed_boxes):
 
     previous_in_flow = None
     for index, child in reversed_enumerate(children):
+        if isinstance(child, boxes.TableRowGroupBox) and (
+                child.is_header or child.is_footer):
+            # We don’t want to break pages before table headers or footers.
+            continue
+
         if child.is_in_normal_flow():
             if previous_in_flow is not None and (
                     block_level_page_break(child, previous_in_flow) not in
@@ -810,6 +815,7 @@ def find_earlier_page_break(children, absolute_boxes, fixed_boxes):
                 resume_at = (children[index].index, None)
                 break
             previous_in_flow = child
+
         if child.is_in_normal_flow() and (
                 child.style['break_inside'] not in ('avoid', 'avoid-page')):
             breakable_box_types = (

weasyprint/layout/tables.py

@@ -278,12 +278,14 @@ def body_groups_layout(skip_stack, position_y, max_position_y,
         next_page = {'break': 'any', 'page': None}
 
         for i, group in enumerate(table.children[skip:]):
-            index_group = i + skip
-            group.index = index_group
-
             if group.is_header or group.is_footer:
                 continue
 
+            # Index is useless for headers and footers, as we never want to
+            # break pages after the header or before the footer.
+            index_group = i + skip
+            group.index = index_group
+
             if new_table_children:
                 page_break = block_level_page_break(
                     new_table_children[-1], group)

weasyprint/tests/test_layout/test_table.py

@@ -2032,7 +2032,7 @@ def test_table_page_breaks(html, rows, positions):
 
 
 @assert_no_logs
-def test_table_page_breaks_complex():
+def test_table_page_breaks_complex_1():
     pages = render_pages('''
       <style>
         @page { size: 100px }
@@ -2085,6 +2085,66 @@ def test_table_page_breaks_complex():
     ]
 
 
+@assert_no_logs
+def test_table_page_breaks_complex_2():
+    pages = render_pages('''
+      <style>
+        @page { size: 250px }
+        td { height: 40px }
+        table { table-layout: fixed; width: 100%; break-before: avoid }
+      </style>
+      <table>
+        <thead>
+          <tr><td>head 1</td></tr>
+        </thead>
+        <tbody>
+          <tr><td>row 1 1</td></tr>
+          <tr><td>row 1 2</td></tr>
+          <tr><td>row 1 3</td></tr>
+        </tbody>
+        <tfoot>
+          <tr><td>foot 1</td></tr>
+        </tfoot>
+      </table>
+      <table>
+        <thead>
+          <tr><td>head 2</td></tr>
+        </thead>
+        <tbody>
+          <tr><td>row 2 1</td></tr>
+          <tr><td>row 2 2</td></tr>
+          <tr><td>row 2 3</td></tr>
+        </tbody>
+        <tfoot>
+          <tr><td>foot 2</td></tr>
+        </tfoot>
+      </table>
+     ''')
+    rows_per_page = []
+    for i, page in enumerate(pages):
+        groups = []
+        html, = page.children
+        body, = html.children
+        for table_wrapper in body.children:
+            table, = table_wrapper.children
+            for group in table.children:
+                assert group.children, 'found an empty table group'
+                rows = []
+                for row in group.children:
+                    cell, = row.children
+                    line, = cell.children
+                    text, = line.children
+                    rows.append(text.text)
+                groups.append(rows)
+        rows_per_page.append(groups)
+    assert rows_per_page == [
+        [['head 1'], ['row 1 1'], ['row 1 2'], ['foot 1']],
+        [['head 1'], ['row 1 3'], ['foot 1'],
+         ['head 2'], ['row 2 1'], ['foot 2']],
+        [['head 2'], ['row 2 2'], ['row 2 3'], ['foot 2']],
+    ]
+
+
 @assert_no_logs
 def test_table_page_break_after():
     page1, page2, page3, page4, page5, page6 = render_pages('''