Handle recto/verso on page break.

Author: grewn0uille

weasyprint/layout/pages.py

@@ -716,9 +716,16 @@ def remake_page(index, context, root_box, html, style_for):
     page_state = copy.deepcopy(initial_page_state)
     next_page_name = initial_next_page['page']
     first = index == 0
-    # TODO: handle recto/verso and add test
-    blank = ((initial_next_page['break'] == 'left' and right_page) or
-             (initial_next_page['break'] == 'right' and not right_page))
+    if initial_next_page['break'] in ('left', 'right'):
+        next_page_side = initial_next_page['break']
+    elif initial_next_page['break'] in ('recto', 'verso'):
+        direction_ltr = root_box.style['direction'] == 'ltr'
+        break_verso = initial_next_page['break'] == 'verso'
+        next_page_side = 'right' if direction_ltr ^ break_verso else 'left'
+    else:
+        next_page_side = None
+    blank = ((next_page_side == 'left' and right_page) or
+             (next_page_side == 'right' and not right_page))
     if blank:
         next_page_name = ''
     side = 'right' if right_page else 'left'

weasyprint/tests/test_layout/test_page.py

@@ -497,6 +497,29 @@ def test_margin_break_clearance():
     assert div_2.content_box_y() == 5
 
 
+@assert_no_logs
+@pytest.mark.parametrize('direction, page_break, pages_number', (
+    ('ltr', 'recto', 3),
+    ('ltr', 'verso', 2),
+    ('rtl', 'recto', 3),
+    ('rtl', 'verso', 2),
+    ('ltr', 'right', 3),
+    ('ltr', 'left', 2),
+    ('rtl', 'right', 2),
+    ('rtl', 'left', 3),
+))
+def test_recto_verso_break(direction, page_break, pages_number):
+    pages = render_pages('''
+      <style>
+        html { direction: %s }
+        p { break-before: %s }
+      </style>
+      abc
+      <p>def</p>
+    ''' % (direction, page_break))
+    assert len(pages) == pages_number
+
+
 @assert_no_logs
 def test_page_names_1():
     pages = render_pages('''