v62 - TypeError: can't multiply sequence by non-int of type 'float'

[jbpenrath]

Since I upgraded my project to version 62, I get the following error on PDF generation. It seems to be related to flex layout.

TypeError: can't multiply sequence by non-int of type 'float'

• Platform: Docker - python:3.10-slim-bullseye (Debian 11 bullseye)

• Python: 3.10.14

• Packages:

  • cffi==1.16.0
  • cssselect2==0.7.0
  • fonttools==4.51.0
  • html5lib==1.1
  • pillow==10.3.0
  • pydyf==0.10.0
  • pyphen==0.15.0
  • tinycss2==1.3.0
  • Weasyprint==62.0

Here it is the full log I get :

joanie/core/utils/issuers.py:37: in generate_document
    return doc_html.write_pdf(stylesheets=[css], zoom=1, font_config=font_config)
../../../.local/lib/python3.10/site-packages/weasyprint/__init__.py:259: in write_pdf
    self.render(font_config, counter_style, **options)
../../../.local/lib/python3.10/site-packages/weasyprint/__init__.py:216: in render
    return Document._render(self, font_config, counter_style, options)
../../../.local/lib/python3.10/site-packages/weasyprint/document.py:262: in _render
    [Page(page_box) for page_box in page_boxes],
../../../.local/lib/python3.10/site-packages/weasyprint/document.py:262: in <listcomp>
    [Page(page_box) for page_box in page_boxes],
../../../.local/lib/python3.10/site-packages/weasyprint/layout/__init__.py:130: in layout_document
    pages = list(make_all_pages(context, root_box, html, pages))
../../../.local/lib/python3.10/site-packages/weasyprint/layout/page.py:906: in make_all_pages
    page, resume_at = remake_page(i, context, root_box, html)
../../../.local/lib/python3.10/site-packages/weasyprint/layout/page.py:844: in remake_page
    page, resume_at, next_page = make_page(
../../../.local/lib/python3.10/site-packages/weasyprint/layout/page.py:646: in make_page
    root_box, resume_at, next_page, _, _, _ = block_level_layout(
../../../.local/lib/python3.10/site-packages/weasyprint/layout/block.py:59: in block_level_layout
    return block_level_layout_switch(
../../../.local/lib/python3.10/site-packages/weasyprint/layout/block.py:75: in block_level_layout_switch
    return block_box_layout(
../../../.local/lib/python3.10/site-packages/weasyprint/layout/block.py:124: in block_box_layout
    result = block_container_layout(
../../../.local/lib/python3.10/site-packages/weasyprint/layout/block.py:714: in block_container_layout
    next_page, new_children, new_max_lines) = _in_flow_layout(
../../../.local/lib/python3.10/site-packages/weasyprint/layout/block.py:506: in _in_flow_layout
    collapsing_through, max_lines) = block_level_layout(
../../../.local/lib/python3.10/site-packages/weasyprint/layout/block.py:59: in block_level_layout
    return block_level_layout_switch(
../../../.local/lib/python3.10/site-packages/weasyprint/layout/block.py:82: in block_level_layout_switch
    result = flex_layout(
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

context = <weasyprint.layout.LayoutContext object at 0x7f8d53dba650>
box = <FlexBox body>, bottom_space = 0, skip_stack = None
containing_block = <BlockBox html>, page_is_empty = True, absolute_boxes = []
fixed_boxes = []

    def flex_layout(context, box, bottom_space, skip_stack, containing_block,
                    page_is_empty, absolute_boxes, fixed_boxes):
        from . import block, preferred
    
        context.create_block_formatting_context()
        resume_at = None
    
        # Step 1 is done in formatting_structure.boxes
        # Step 2
        if box.style['flex_direction'].startswith('row'):
            axis, cross = 'width', 'height'
        else:
            axis, cross = 'height', 'width'
    
        margin_left = 0 if box.margin_left == 'auto' else box.margin_left
        margin_right = 0 if box.margin_right == 'auto' else box.margin_right
        margin_top = 0 if box.margin_top == 'auto' else box.margin_top
        margin_bottom = 0 if box.margin_bottom == 'auto' else box.margin_bottom
    
        if getattr(box, axis) != 'auto':
            available_main_space = getattr(box, axis)
        else:
            if axis == 'width':
                available_main_space = (
                    containing_block.width -
                    margin_left - margin_right -
                    box.padding_left - box.padding_right -
                    box.border_left_width - box.border_right_width)
            else:
                main_space = context.page_bottom - bottom_space - box.position_y
                if containing_block.height != 'auto':
                    if isinstance(containing_block.height, Dimension):
                        assert containing_block.height.unit == 'px'
                        main_space = min(main_space, containing_block.height.value)
                    else:
                        main_space = min(main_space, containing_block.height)
                available_main_space = (
                    main_space -
                    margin_top - margin_bottom -
                    box.padding_top - box.padding_bottom -
                    box.border_top_width - box.border_bottom_width)
    
        if getattr(box, cross) != 'auto':
            available_cross_space = getattr(box, cross)
        else:
            if cross == 'height':
                main_space = (
                    context.page_bottom - bottom_space - box.content_box_y())
                if containing_block.height != 'auto':
                    if isinstance(containing_block.height, Dimension):
                        assert containing_block.height.unit == 'px'
                        main_space = min(main_space, containing_block.height.value)
                    else:
                        main_space = min(main_space, containing_block.height)
                available_cross_space = (
                    main_space -
                    margin_top - margin_bottom -
                    box.padding_top - box.padding_bottom -
                    box.border_top_width - box.border_bottom_width)
            else:
                available_cross_space = (
                    containing_block.width -
                    margin_left - margin_right -
                    box.padding_left - box.padding_right -
                    box.border_left_width - box.border_right_width)
    
        # Step 3
        children = box.children
        parent_box = box.copy_with_children(children)
        resolve_percentages(parent_box, containing_block)
        # TODO: removing auto margins is OK for this step, but margins should be
        # calculated later.
        if parent_box.margin_top == 'auto':
            box.margin_top = parent_box.margin_top = 0
        if parent_box.margin_bottom == 'auto':
            box.margin_bottom = parent_box.margin_bottom = 0
        if parent_box.margin_left == 'auto':
            box.margin_left = parent_box.margin_left = 0
        if parent_box.margin_right == 'auto':
            box.margin_right = parent_box.margin_right = 0
        if isinstance(parent_box, boxes.FlexBox):
            block.block_level_width(parent_box, containing_block)
        else:
            parent_box.width = preferred.flex_max_content_width(
                context, parent_box)
        original_skip_stack = skip_stack
        children = sorted(children, key=lambda item: item.style['order'])
        if skip_stack is not None:
            (skip, skip_stack), = skip_stack.items()
            if box.style['flex_direction'].endswith('-reverse'):
                children = children[:skip + 1]
            else:
                children = children[skip:]
            skip_stack = skip_stack
        else:
            skip_stack = None
        child_skip_stack = skip_stack
        for child in children:
            if not child.is_flex_item:
                continue
    
            # See https://www.w3.org/TR/css-flexbox-1/#min-size-auto
            if child.style['overflow'] == 'visible':
                main_flex_direction = axis
            else:
                main_flex_direction = None
            resolve_percentages(child, containing_block, main_flex_direction)
            child.position_x = parent_box.content_box_x()
            child.position_y = parent_box.content_box_y()
            if child.min_width == 'auto':
                specified_size = child.width if child.width != 'auto' else inf
                if isinstance(child, boxes.ParentBox):
                    new_child = child.copy_with_children(child.children)
                else:
                    new_child = child.copy()
                new_child.style = child.style.copy()
                new_child.style['width'] = 'auto'
                new_child.style['min_width'] = Dimension(0, 'px')
                new_child.style['max_width'] = Dimension(inf, 'px')
                content_size = min_content_width(context, new_child, outer=False)
                child.min_width = min(specified_size, content_size)
            elif child.min_height == 'auto':
                # TODO: find a way to get min-content-height
                specified_size = child.height if child.height != 'auto' else inf
                if isinstance(child, boxes.ParentBox):
                    new_child = child.copy_with_children(child.children)
                else:
                    new_child = child.copy()
                new_child.style = child.style.copy()
                new_child.style['height'] = 'auto'
                new_child.style['min_height'] = Dimension(0, 'px')
                new_child.style['max_height'] = Dimension(inf, 'px')
                new_child = block.block_level_layout(
                    context, new_child, -inf, child_skip_stack, parent_box,
                    page_is_empty)[0]
                content_size = new_child.height
                child.min_height = min(specified_size, content_size)
    
            child.style = child.style.copy()
    
            if child.style['flex_basis'] == 'content':
                flex_basis = child.flex_basis = 'content'
            else:
                resolve_one_percentage(child, 'flex_basis', available_main_space)
                flex_basis = child.flex_basis
    
            # "If a value would resolve to auto for width, it instead resolves
            # to content for flex-basis." Let's do this for height too.
            # See https://www.w3.org/TR/css-flexbox-1/#propdef-flex-basis
            resolve_one_percentage(child, axis, available_main_space)
            if flex_basis == 'auto':
                if child.style[axis] == 'auto':
                    flex_basis = 'content'
                else:
                    if axis == 'width':
                        flex_basis = child.border_width()
                        if child.margin_left != 'auto':
                            flex_basis += child.margin_left
                        if child.margin_right != 'auto':
                            flex_basis += child.margin_right
                    else:
                        flex_basis = child.border_height()
                        if child.margin_top != 'auto':
                            flex_basis += child.margin_top
                        if child.margin_bottom != 'auto':
                            flex_basis += child.margin_bottom
    
            # Step 3.A
            if flex_basis != 'content':
                child.flex_base_size = flex_basis
    
            # TODO: Step 3.B
            # TODO: Step 3.C
    
            # Step 3.D is useless, as we never have infinite sizes on paged media
    
            # Step 3.E
            else:
                child.style[axis] = 'max-content'
    
                # TODO: don't set style value, support *-content values instead
                if child.style[axis] == 'max-content':
                    child.style[axis] = 'auto'
                    if axis == 'width':
                        child.flex_base_size = max_content_width(context, child)
                    else:
                        if isinstance(child, boxes.ParentBox):
                            new_child = child.copy_with_children(child.children)
                        else:
                            new_child = child.copy()
                        new_child.width = inf
                        new_child = block.block_level_layout(
                            context, new_child, -inf, child_skip_stack, parent_box,
                            page_is_empty, absolute_boxes, fixed_boxes)[0]
                        child.flex_base_size = new_child.margin_height()
                elif child.style[axis] == 'min-content':
                    child.style[axis] = 'auto'
                    if axis == 'width':
                        child.flex_base_size = min_content_width(context, child)
                    else:
                        if isinstance(child, boxes.ParentBox):
                            new_child = child.copy_with_children(child.children)
                        else:
                            new_child = child.copy()
                        new_child.width = 0
                        new_child = block.block_level_layout(
                            context, new_child, -inf, child_skip_stack, parent_box,
                            page_is_empty, absolute_boxes, fixed_boxes)[0]
                        child.flex_base_size = new_child.margin_height()
                else:
                    assert child.style[axis].unit == 'px'
                    # TODO: should we add padding, borders and margins?
                    child.flex_base_size = child.style[axis].value
    
            child.hypothetical_main_size = max(
                getattr(child, f'min_{axis}'), min(
                    child.flex_base_size, getattr(child, f'max_{axis}')))
    
            # Skip stack is only for the first child
            child_skip_stack = None
    
        # Step 4
        # TODO: the whole step has to be fixed
        if axis == 'width':
            block.block_level_width(box, containing_block)
        else:
            if box.style['height'] != 'auto':
                if box.style['height'].unit == '%':
>                   box.height = box.style['height'].value / 100. * containing_block.height
E                   TypeError: can't multiply sequence by non-int of type 'float'

[liZe]

Thanks for the report. The crash has been fixed, but the size of the flex item is still wrong (it was wrong too in 61).

Related to #2135.