Before this change AddClipRect was a "special" because it didn't respect
scroll frame offset and was meant to be recorded using viewport-relative
coordinates. The motivation behind this was to record a "final" clip
rectangle computed by intersecting all clip rectangles used by a clip
frame. The disadvantage of this approach is that it blocks us from
implementing an optimisation to reuse display list if the only change is
in the scroll offset, because any scroll offset change leads to
invalidating all AddClipRect items within a list.
This change aligns AddClipRect with the rest of display list items by
making it account for scroll frame offset. It required discontinuing
the recording of the intersection of all clip rectangles within a clip
frame and instead producing an AddClipRect for each of them.
A nice side effect is the removal of code that shifts clip rectangle by
`enclosing_scroll_offset()` in a bunch of places, because now it happens
automatically in `DisplayList::apply_scroll_offsets()`.
This change causes the viewport to be treated as a "scroll frame,"
similar to how it already works for boxes with "overflow: scroll."
This means that, instead of encoding the viewport translation into a
display list, the items will be assigned the scroll frame id of the
viewport and then shifted by the scroll offset before execution. In the
future it will allow us to reuse a display list for repainting if only
scroll offset has changed.
As a side effect, it also removes the need for special handling of
"position: fixed" because compensating for the viewport offset while
painting or hit-testing is no longer necessary. Instead, anything
contained within a "position: fixed" element is simply not assigned
a scroll frame id, which means it is not shifted by the scroll offset.
This fixes a crash using URLSearchParams when provided a percent encoded
string which does not percent decode to valid UTF-8.
Fixes a crash running https://wpt.live/url/urlencoded-parser.any.html
There are (currently) no spec-tests ensuring that section ordering is
enforced, but it _is_ a part of the spec. A pull request to add this to
the specification testsuite has been opened at WebAssembly/spec#1775.
While introducing clip and scroll frame trees, I made a mistake by
assuming that the paintable tree includes boxes from nested navigables.
Therefore, this comment in the code was incorrect, and clip/scroll
frames were simply not assigned for iframes:
// NOTE: We only need to refresh the scroll state for traversables
// because they are responsible for tracking the state of all
// nested navigables.
As a result, anything with "overflow: scroll" is currently not
scrollable inside an iframe
This change fixes that by ensuring clip and scroll frames are assigned
and refreshed for each navigable. To achieve this, I had to modify the
display list building process to record a separate display list for each
navigable. This is necessary because scroll frame ids are local to a
navigable, making it impossible to call
`DisplayList::apply_scroll_offsets()` on a display list that contains
ids from multiple navigables.
In calculating the base size of a flex item, we have a piece of ad-hoc
code that deals with an item that does have an instrinsic aspect ratio,
but not a cross size to resolve that ratio against. In determining the
actual flex item size however, we also take into account the minimum
content width and height, which assumes the box' intrinsic width or
height when available. This would break having an image as a flex item,
which gets stretched to its maximum size within the flex container
instead of the flex item being shrunk to the instrinsic size of the
image.
Fix this by only stretching flex items that do not have an instrinsic
width nor height set.
Implements the corresponding encoders, selects the appropriate one when
encoding URL search params. If an encoder for the given encoding could
not be found, fallback to utf-8.
`m_needs_repaint = true` is not enough because it doesn't schedule
repaint of a parent navigable.
Fixes the bug when an iframe is not repainted after scrolling.
