Previously, has_scrollable_overflow was a purely geometric check, true
whenever content extended beyond the padding box regardless of the
overflow property. This caused unnecessary scroll frame allocation for
boxes with `overflow:visible`.
Per CSS Overflow 3, scrollable overflow is only defined for scroll
containers (overflow: auto/hidden/scroll). Gate the flag on
`is_scroll_container()` so that only actual scroll containers get scroll
frames assigned.
This change removes premature reset of
`block_container_y_position_update_callback`. Also makes callback
private in `BlockMarginState`, because resetting it independently of
currently accumulated margins is incorrect.
Lots of test expectations are updated, but there is no visual
difference.
Fixes https://github.com/LadybirdBrowser/ladybird/issues/6074
Inline nodes in our layout tree have a position, so let's show it. By
centralizing the logic for this, block nodes now lose their redundant
'content-size' dump info which is already part of the box model dump.
...with inline children. This fixes an issue when we ignore abspos boxes
contained by PaintableWithLines while calculating overflow rect size.
Lots of layout tests are affected, because now PaintableWithLines has
overflow rect.
`Text/input/DOM/Element-set-scroll-left.html` is also affected and now
matches other browsers.
Browsers such as Chrome and Firefox apply an arbitrary scale to the
current font size if `normal` is used for `line-height`. Firefox uses
1.2 while Chrome uses 1.15. Let's go with the latter for now, it's
relatively easy to change if we ever want to go back on that decision.
This also requires updating the expectations for a lot of layout tests.
The upside of this is that it's a bit easier to compare our layout
results to other browsers', especially Chrome.
Whenever we introduce a block element in a container that at that point
has only had inline children, we create an anonymous wrapper for all the
inline elements so we can keep the invariant that each container
contains either inline or non-inline children. For some reason, we
ignore all the out-of-flow nodes since they are layed out separately and
it was thought that this shouldn't matter.
However, if we are dealing with inline blocks and floating blocks, the
order of the inline contents _including_ out-of-flow nodes becomes very
important: floating blocks need to take the order of nodes into account
when positioning themselves.
Fix this by simply hoisting the out-of-flow nodes into the anonymous
wrapper as well.
Fixes the order of blocks in #4212. The gap is still not present.
