Stop rendering when column content doesn’t fit in the page

Author: liZe

tests/layout/test_column.py

@@ -301,6 +301,88 @@ def test_column_span_6():
     assert section.children[0].children[0].text == 'line1'
     assert (section.position_x, section.position_y) == (0, 0)
 
+
+@assert_no_logs
+def test_column_span_7():
+    page1, page2 = render_pages('''
+      <style>
+        @font-face { src: url(weasyprint.otf); font-family: weasyprint }
+        @page { margin: 0; size: 8px 3px }
+        body { font-family: weasyprint; font-size: 1px }
+        div { columns: 2; column-gap: 0; line-height: 1 }
+        section { column-span: all; font-size: 2px }
+      </style>
+      <div>
+        abc def
+        ghi jkl
+        <section>l1</section>
+        mno pqr
+      </div>
+    ''')
+    html, = page1.children
+    body, = html.children
+    div, = body.children
+    column1, column2 = div.children
+    assert (column1.position_x, column1.position_y) == (0, 0)
+    assert (column2.position_x, column2.position_y) == (4, 0)
+
+    assert column1.children[0].children[0].children[0].text == 'abc'
+    assert column1.children[0].children[1].children[0].text == 'def'
+    assert column2.children[0].children[0].children[0].text == 'ghi'
+    assert column2.children[0].children[1].children[0].text == 'jkl'
+
+    html, = page2.children
+    body, = html.children
+    div, = body.children
+    section, column1, column2 = div.children
+    assert (section.position_x, section.position_y) == (0, 0)
+    assert (column1.position_x, column1.position_y) == (0, 2)
+    assert (column2.position_x, column2.position_y) == (4, 2)
+
+    assert section.children[0].children[0].text == 'l1'
+    assert column1.children[0].children[0].children[0].text == 'mno'
+    assert column2.children[0].children[0].children[0].text == 'pqr'
+
+
+@assert_no_logs
+def test_column_span_8():
+    page1, page2 = render_pages('''
+      <style>
+        @font-face { src: url(weasyprint.otf); font-family: weasyprint }
+        @page { margin: 0; size: 8px 2px }
+        body { font-family: weasyprint; font-size: 1px }
+        div { columns: 2; column-gap: 0; line-height: 1 }
+        section { column-span: all }
+      </style>
+      <div>
+        abc def
+        ghi jkl
+        mno pqr
+        <section>line1</section>
+      </div>
+    ''')
+    html, = page1.children
+    body, = html.children
+    div, = body.children
+    column1, column2 = div.children
+    assert (column1.position_x, column1.position_y) == (0, 0)
+    assert (column2.position_x, column2.position_y) == (4, 0)
+
+    assert column1.children[0].children[0].children[0].text == 'abc'
+    assert column1.children[0].children[1].children[0].text == 'def'
+    assert column2.children[0].children[0].children[0].text == 'ghi'
+    assert column2.children[0].children[1].children[0].text == 'jkl'
+
+    html, = page2.children
+    body, = html.children
+    div, = body.children
+    column1, column2, section = div.children
+    assert (column1.position_x, column1.position_y) == (0, 0)
+    assert (column2.position_x, column2.position_y) == (4, 0)
+    assert (section.position_x, section.position_y) == (0, 1)
+
+    assert column1.children[0].children[0].children[0].text == 'mno'
+    assert column2.children[0].children[0].children[0].text == 'pqr'
     assert section.children[0].children[0].text == 'line1'
 
 

weasyprint/layout/column.py

@@ -174,6 +174,7 @@ def create_column_box(children):
         first_probe_run = True
         original_page_is_empty = page_is_empty
         page_is_empty = False
+        stop_rendering = False
         while True:
             column_skip_stack = skip_stack
 
@@ -251,6 +252,7 @@ def create_column_box(children):
                 if column_skip_stack or max(consumed_heights) > max_height:
                     # Even at maximum height, not everything fits. Stop now and
                     # let the columns continue on the next page.
+                    stop_rendering = True
                     break
                 else:
                     # Everything fit, start expanding columns at the average of
@@ -274,6 +276,7 @@ def create_column_box(children):
 
                     if height + add_height > max_height:
                         height = max_height
+                        stop_rendering = True
                         break
 
                     height += add_height
@@ -328,6 +331,9 @@ def create_column_box(children):
         skip_stack = None
         page_is_empty = False
 
+        if stop_rendering:
+            break
+
     if box.children and not new_children:
         # The box has children but none can be drawn, let's skip the whole box
         context.in_column = False