Firefox 74 Platform Layout Release Notes

Noteworthy Changes

Features

• `text-underline-offset` and `text-decoration-thickness` now accept percentage values (bug 1607534)
• Support viewport-fit property on meta viewport (bug 1574307)

All Bugs Fixed

CSS Parsing and Computation

bug 1606503 ubuntu1804 - layout/style/test/test_mq_prefers_reduced_motion_dynamic.html | Does not matches prefers-reduced-motion: reduced) when the system sets prefers-reduced-motion false

bug 1606628 Remove nsStyleImageRequest.

bug 1606997 Let CSS text-underline-position property ride the train to release

bug 1607006 Remove utf-16 versions of nsCSSProps::LookupProperty* and ServoCSSParser::ComputeColor.

bug 1607049 Refactor LengthPercentage to move the calc() variant to the heap.

bug 1607135 Remove unnecessary TriggerImageLoads

bug 1607308 wrong text-underline-offset zero position with text-underline-position:under

bug 1607534 `text-underline-offset` and `text-decoration-thickness` should accept percentage values

bug 1607716 Crash in [@ selectors::parser::Template:Impl::to_shmem<T>]

bug 1607952 Construction of ComputedGridTrackInfo uses a method and std::move on the same variable

bug 1607959 Clarify StyleSheet Parsing Documentation

bug 1608907 Remove layout.css.parsing.parallel.

bug 1609256 Centralize calc() parsing.

bug 1609428 Implement min() / max() / clamp() for simple css types behind a pref.

bug 1609489 Remove lazy_static usage from custom_properties.rs.

bug 1609737 Forbid accessing the length and percentage parts of a LengthPercentage separately.

bug 1610059 Rename Document::SetStyleSheetApplicableState.

bug 1610064 Avoid including StyleSheet.h from document.h

bug 1610164 The adoptedStyleSheets getter shouldn't be marked as throwing

bug 1610801 Remove keyword calc() font-size hack.

bug 1611040 Convert dominant-baseline #defines to an enum class.

bug 1611041 Convert image-rendering #defines to an enum class.

bug 1611043 Convert mask-type #defines to an enum class.

bug 1611044 Convert stroke-linejoin #defines to an enum class.

bug 1611181 Make direction use an enum class.

bug 1611583 Use cbindgen for css-align types.

bug 1611711 Remove kCursorKTable.

bug 1611713 Remove TextControlState::GetParentNumberControl

bug 1611733 Convert NS_STYLE_POSITION_* definitions to an enum class in nsStyleConsts.h

bug 1611829 Convert scroll-behavior #defines to an enum class.

bug 1611912 Make the computed style know whether it's the root element style.

bug 1612114 ShadowRoot style data doesn't get invalidated properly on insertion if there are no stylesheets when it gets inserted in the document

bug 1612143 Convert table-layout #defines to an enum class.

bug 1612146 Convert empty-cells #defines to an enum class.

bug 1612148 Convert transform-style #defines to an enum class.

bug 1612301 Hit MOZ_CRASH(assertion failed: `(left == right)` left: `Length`, right: `Calc`) at servo/components/style/values/computed/length_percentage.rs:238 on big endian machine

bug 1613006 Update smallvec.

bug 1613010 Don't use a binary tree representation for calc() sums / products.

bug 1613257 InspectorUtils.cpp: redundant return statement at the end of a function with a void return type

bug 1614160 Add AngleOrPercentage to style system

CSS Transitions and Animations

bug 1591629 No need to pass TransformData for all transform-like properties to compositor

bug 1592822 Use serde to serialize more types whose animations could run on the compositor (for IPC layers)

DOM: CSS Object Model

bug 1606727 Implement CSSStyleSheet Constructor

bug 1607080 Avoid silly UTF-16 -> UTF-8 conversion in DOMMatrix.

bug 1607268 Implement CSSStyleSheet ReplaceSync() Functionality

bug 1608488 Add the adoptedStyleSheets attribute to the DocumentOrShadowRoot WebIDL interface

Layout

bug 1031664 Enable rendering of outline-style:auto by default

bug 1155772 Convert flex item margin/border/padding computations to use logical axes

bug 1310792 [css-grid] grid-item-content-baseline-* and grid-item-mixed-baseline-* are disabled (random) because they depend on font metrics

bug 1541095 Try to use typed enums to avoid need for static_casts in WritingModes.h

bug 1570363 transform-origin incorrectly calculated for fill boxes that have zero width or height

bug 1574307 Implement viewport-fit property into meta viewport

bug 1597055 Not setting max-height causes position: sticky to break

bug 1598751 Remove w3c-css/received/css-conditional reftests

bug 1607123 Consider destroying AccesibleCaretEventHub after tearing down frame tree

bug 1607316 Implement separate fingerprinting resistance treatment of @media interaction features for desktop and android

bug 1607408 Remove InspectorUtils.getBindingURLs.

bug 1607658 Intermittent layout/generic/crashtests/1032450.html | assertion count 358 is more than expected 0 to 24 assertions

bug 1607826 Use standard type traits in layout.

bug 1607964 ubuntu1804 - TEST-UNEXPECTED-PASS | layout/reftests/bugs/reftest.list | adjust expectations for linux1804 and fission

bug 1608063 Remove TypeTraits usage from layout/

bug 1608931 A huge amount of Puppeteer unit tests hang in `Runtime.callFunctionOn` when using IntersectionObserver

bug 1609786 AddressSanitizer: SEGV /builds/worker/fetches/clang/bin/../lib/gcc/x86_64-unknown-linux-gnu/7.4.0/../../../../include/c++/7.4.0/bits/atomic_base.h:524:16 in fetch_sub

bug 1610085 No longer possible to override link color

bug 1610387 Replace nsAutoPtr usage in layout/ with UniquePtr

bug 1610404 Remove nsGroupBoxFrame (display: -moz-groupbox)

bug 1610670 Create iterable collections for all values for LogicalSide, mozilla::Side, etc to support range-for loop

bug 1611038 Assertion failure: !mResizeEventFlushObservers.Contains(aPresShell) && !mDelayedResizeEventFlushObservers.Contains(aPresShell) (Double-adding resize event flush observer), at nsRefreshDriver.h:197

bug 1611117 Remove unused includes from nsNumberControlFrame

bug 1611118 Fix invalid selectors in forms.css

bug 1612444 Add better error messages for some places where we throw DOMExceptions in layout code

bug 1613192 Fix non-unified build errors in layout/base and layout/generic

bug 1613198 Move nsIFrame::GetNormalPosition and GetLogicalNormalPosition into nsIFrameInlines.h

bug 1613349 Make nsIFrame::RemoveProperty `MOZ_MUST_USE`.

bug 1614165 Improve some more exception messages in layout

Layout: Columns

bug 1308636 Remove support for -moz-prefixed CSS multi-column properties

bug 1603088 max-block-size:100% on anonymous column layout boxes makes no sense

Layout: Flexbox

bug 1609506 Extract computation of ComputedFlex{Container,Line,Item}Info into helper methods

bug 1609847 Remove "Get" prefix for simple accessors in flex container and other helper classes

bug 1612401 Absolutely positioned flex item leaves a gap

bug 1613380 Assertion failure: mNumAutoMarginsInMainAxis == 0 (miscounted the number of auto margins), at /builds/worker/workspace/build/src/layout/generic/nsFlexContainerFrame.cpp:2242

bug 1613732 Revise ReflowChildFlags comments, and use logical ReflowChild and FinishReflowChild in flex container

bug 1614082 Minor flexbox cleanup

Layout: Floats

bug 1611314 Intermittent /css/css-shapes/shape-outside/shape-image/gradients/shape-outside-linear-gradient-013.html | Testing http://web-platform.test:8000/css/css-shapes/shape-outside/shape-image/gradients/shape-outside-linear-gradient-013.html

Layout: Form Controls

bug 981248 <input> has focus/blur issues when it has focus and its type changes to/from type=number

bug 1105920 html5 input type="number" with an associated datalist does not indicate that a datalist is present

bug 1430141 Input elements with number type overflow parent in flex layout

bug 1484213 Intermittent dom/tests/browser/browser_autofocus_background.js | The background tab's focused element should be INPUT - Got BODY, expected INPUT

bug 1608006 Perma [tier 2] linux1804 TEST-UNEXPECTED-PASS | layout/forms/test/test_bug549170.html | fail-if condition in manifest - We expected at least one failure

bug 1611661 Number inputs in Google calendar don't work right with arrow keys

bug 1611701 Dropping text into an <input type=number> broke with bug 981248.

Layout: Generated Content, Lists, and Counters

bug 1605349 Fix expectation for marker-content-010.html WPT test

Layout: Grid

bug 1599206 [css-grid] Exclude implicit tracks from grid-template-rows/columns resolved values

bug 1606485 crash near null in [@ mozilla::ReflowInput::InitConstraints]

bug 1606516 Hit MOZ_CRASH(ElementAt(aIndex = 0, aLength = 0)) in [@ CopyUsedTrackSizes]

bug 1610362 floor subgrid track sizes to zero

bug 1611724 [css-grid] align-content:baseline fails for single-line block grid items

bug 1611950 Make nsGridContainerFrame::Grid::CellMap::Cell constexpr

bug 1611951 Add basic documentation of the members of ComputedGridTrackInfo

Layout: Positioned

bug 1611462 We end up reframing the URL bar during startup

Layout: Ruby

bug 1513275 MOZ_ASSERT_UNREACHABLE: Any line break inside ruby box should have been suppressed), at /builds/worker/workspace/build/src/layout/generic/nsRubyBaseContainerFrame.cpp:625

bug 1603354 Ruby in Firefox 71 is displaying incorrectly.

Layout: Scrolling and Overflow

bug 1602088 Move nsIScrollableFrame::ScrollUnit to namespace scope

bug 1610849 [css-scroll-anchoring] [css-scroll-snap] What's the optimal viewing rect on the root scroller?

bug 1613094 The parameter 'aStartPos' should use const reference.

Layout: Tables

bug 1613834 Redundant condition in nsTableCellMap::RemoveColsAtEnd

Layout: Text and Fonts

bug 1293584 CSS "word-break: keep-all;" fails to break the text at CJK punctuations

bug 1604464 Create WPT reftests for rendering of text-decoration lines across descendants of the decorating box

bug 1605265 Border around focused CC-BY-SA link has broken design, justify bugs

bug 1606209 HYPHENATION_* telemetry will expire in Nightly on 2020-01-06 when the Gecko version increases to 74

bug 1606305 Wrong intrinsic width for pre element with font-size: 0.

bug 1608100 Distinguish (in console log messages) between failure to start font download at all vs download that fails

bug 1608124 [shared font list] macOS "hidden" system font families should not be recognized in the CSS `font-family` list

bug 1609730 `text-underline-position:left` and `right` values should be ignored in vertical-sideways writing modes

bug 1611589 Incorrect precedence of font features vs letter-spacing

bug 1611591 Spurious failure in WPT testcase font-synthesis-05.html

bug 1611610 synthetic-bold effect should not increase the advance of zero-width glyphs

bug 1611997 Variable fonts with slant axis not slanting correctly for font-style positive values

bug 1612399 `text-combine-upright` should not have any effect in sideways-* writing modes

bug 1612822 Refactor & clean up computation of decoration line position/thickness

bug 1613285 Text decorations look off with latest builds.

bug 1613572 Bug 1612822 broke the thickness of the spell-checking underline

Printing: Output

bug 1608018 changing document.title then printing shows the old title in the page headers

SVG

bug 984461 Remove nsIDOMSVGLength from the Components shim

bug 1605687 nsFilterInstance.cpp: Value stored to 'filterIsNoop' is never read

bug 1609856 Stop using NS_ERROR_DOM_TYPE_ERR in SVG code