Firefox 73 Platform Layout Release Notes

Noteworthy Changes

Features

• Support CSS text-underline-position (bug 770780)
• Support logical versions of CSS overscroll-behavior (bug 1453472)

All Bugs Fixed

CSS Parsing and Computation

bug 687441 Subframes can cause a flash of unstyled content (FOUC)

bug 770780 Implement CSS3 text module text-underline-position

bug 1453472 Add overscroll-behavior-{block,inline} properties in addition to overscroll-behavior-{x,y}

bug 1486964 Drop -moz-touch-enabled

bug 1598600 Refactor InvalidationMap flags to use bitflags

bug 1599921 Make rust atom!() actually generate consts.

bug 1600443 Update cssparser.

bug 1600481 convert NS_STYLE_ISOLATION_* to an enum class in nsStyleConsts.h

bug 1600482 convert NS_STYLE_RUBY_POSITION_* to an enum class in nsStyleConsts.h

bug 1600624 Intermittent Assertion failure: aSheet->GetOwnerRule(), at z:/build/build/src/layout/style/StyleSheet.cpp:614

bug 1600735 crash in [@ Servo_IsUnknownPropertyRecordedInUseCounter]

bug 1601025 Optimize change-hint for text decoration changes that don't affect layout

bug 1601856 convert NS_STYLE_VISIBILITY_* to an enum class in nsStyleConsts.h

bug 1601990 convert NS_STYLE_POINTER_EVENTS_* to an enum class in nsStyleConsts.h

bug 1602317 Use nicer cbindgen bitflags.

bug 1603534 Merge ShadowRoot::StyleSheets() and Document::StyleSheets()

bug 1604023 Firefox built with GCC 10 snapshots crashes due to Rust ABi compatibility bug

bug 1604062 Use less app units in the style system's font code.

bug 1604063 Make LengthPercentage not copy.

bug 1604076 Fix some issues with StyleBox.

bug 1604160 Update cbindgen again to generate proper copy-assignment operators.

bug 1604173 Sync servo stuff.

bug 1605418 use GeneratedFile template in layout/style/test/gtest/

bug 1605803 content property of getComputedStyle is being returned as none

bug 1606019 Remove some useless code to refcount nsIReferrerInfo from rust.

bug 1607069 Simplify some serialization code in glue.rs.

CSS Transitions and Animations

bug 1601486 Motion path is not correct for <g> SVG elements with transform-box:fill-box

DOM: CSS Object Model

bug 1594241 CSSOM cssText property is missing styles from stylesheet

bug 1603160 Allow MediaQueryList to receive untrusted events.

bug 1604296 Create Constructable Stylesheets WebIDL API Under a Preference

Layout

bug 1470436 thead overlaps tbody when using page-break-(after/before) property

bug 1514429 window.innerWidth/innerHeight should return the dimensions of the layout viewport

bug 1523541 window.innerHeight changes with the dynamic toolbar on Firefox

bug 1571285 Scrollbars in trees are light with dark theme

bug 1577084 fission iframes that are scrolled far out of view and not painted or visible are set to active

bug 1581467 Do not use synthetic display-inside values.

bug 1582363 Dragging text selection markers selects the wrong text on Android with layout.reflow.synthMouseMove=true

bug 1593362 crash near null in [@ nsFrame::HandleDrag]

bug 1594099 readability backplate spills out left side of text

bug 1596317 Make MediaFeatureValuesChangedAllDocuments work in Fission

bug 1598749 Remove w3c-css/received/css-namespaces reftests

bug 1598755 Remove w3c-css/received/selectors reftests

bug 1600372 nsIDOMWindowUtils.nodesFromRect with aOnlyVisible sometimes includes non-visible items

bug 1600998 Remove layout.css.xul-box-display-values.survive-blockification.enabled pref

bug 1601083 Add an API that returns an element's containing block

bug 1602003 Assertion failure: mPresContext->GetVisibleArea().height != nscoord((1 << 30) - 1) (height should not be NS_UNCONSTRAINEDSIZE after reflow), at /builds/worker/workspace/build/src/layout/base/PresShell.cpp:1977

bug 1602047 Firefox no reset height for images with empty src attrib

bug 1602322 Enable browser.tabs.remote.dataUriInDefaultWebProcess for fission reftests to get better test coverage

bug 1602407 Add wiki.m.o continuation model link to some in-tree documents

bug 1602421 Minor include cleanup.

bug 1602767 Make layout debugger's paged mode use the same setup as reftest-paged

bug 1603773 Disable the MathML mfenced element by default in all builds

bug 1603995 Dead assignments in nsFrame::BoxReflow

bug 1604009 Dead assignments in nsGridRowGroupLayout::CountRowsColumns and nsGridRowGroupLayout::BuildRows

bug 1604011 Dead assignment in StreamLoader::OnStopRequest

bug 1604393 Dead assignment in nsImageFrame::DisplayAltFeedbackWithoutLayer

bug 1604394 Dead assignment in nsIFrame::PeekOffset

bug 1604588 ubuntu1804 - /css/vendor-imports/mozilla/mozilla-central-reftests/background/border-image-repeat-round-1.html | Testing http://web-platform.test:8000/css/vendor-imports/mozilla/mozilla-central-reftests/background/border-image-repeat-round-1.html ==

bug 1604668 Remove the eExcludesIgnorableWhitespace IsFrameOfType bit

bug 1604771 Remove the eSVGForeignObject IsFrameOfType bit

bug 1604772 Remove the eSVGGeometry IsFrameOfType bit

bug 1604978 Move NS_BLOCK_FLAGS_MASK and NS_BLOCK_FLAGS_NON_INHERITED_MASK into nsBlockFrame::Init.

bug 1605414 Perma crashtest failures on several files with | load failed: timed out waiting for spell checks to end | load failed: timed out waiting for reftest-wait to be removed - when Gecko 73 merges to Beta on 2020-01-06

bug 1605466 Miscellaneous include-what-you-use fixes

bug 1606192 Remove some unused nsresult return value in layout code

Layout: Block and Inline

bug 1602430 min/max-height is applied incorrectly in fragmented flow

Layout: Columns

bug 1499281 Remove preference "layout.css.column-span.enabled" after it reaches the release channel

Layout: Flexbox

bug 1601298 Initialize flex container and its helper classes' members in the declaration

Layout: Form Controls

bug 1600202 ubuntu1804 - layout/forms/test/test_bug717878_input_scroll.html | overflow scrollTopMax == 0 - didn't expect +0, but got it

bug 1600207 use-after-poison in [@ mozilla::ReflowInput::ReflowInput]

bug 1600367 crash at null in [@ nsFieldSetFrame::GetNaturalBaselineBOffset]

bug 1600790 ubuntu1804 - forms/input/color/transformations-1.html == forms/input/color/transformations-1-ref.html | image comparison, max difference: 7, number of differing pixels: 113

bug 1602980 Intermittent forms/input/color/transformations-1.html == forms/input/color/transformations-1-ref.html | image comparison, max difference: 1, number of differing pixels: 1

Layout: Generated Content, Lists, and Counters

bug 1601026 Some WPT tests for ::marker use non-allowed properties

Layout: Grid

bug 1601500 ubuntu1804 - /css/css-grid/grid-model/grid-container-scrollbar-vertical-rl-001.html | Testing http://web-platform.test:8000/css/css-grid/grid-model/grid-container-scrollbar-vertical-rl-001.html

Layout: Ruby

bug 1134069 Submit appropriate CSS Ruby tests to W3C test suite

bug 1144465 Text inside ruby is not bidi reordered

Layout: Scrolling and Overflow

bug 1603807 division by zero in layout/generic/nsGfxScrollFrame.cpp:2595

bug 1605956 Invalidate scroll anchor less on visual viewport offset updates

Layout: Tables

bug 1562840 Intermittent table-anonymous-boxes/490174-1.html == table-anonymous-boxes/490174-1-ref.html | image comparison, max difference: 4, number of differing pixels: 1

bug 1604099 Redundant call to GetColCount in nsCellMap::ShrinkWithoutCell

Layout: Text and Fonts

bug 1592057 ubuntu1804 - font-matching/emoji-fallback-1.html, emoji-fallback-3.html

bug 1599841 Combination of unicode-bidi: bidi-override, Arabic subtending mark, and a CSS counter value makes single digits disappear

bug 1602554 Intermittent /css/css-text/text-transform/text-transform-capitalize-003.html | Testing http://web-platform.test:8000/css/css-text/text-transform/text-transform-capitalize-003.html == http://web-platform.test:8000/css/css-text/text-transform/referen

bug 1603458 Distinguish between Error and Warning messages from OTS in the web console

bug 1603665 nsFontFaceUtils::MarkDirtyForFontChange spends too much time doing string conversion

Printing: Output

bug 1017137 Firefox can't print long lists properly from http://chem.sis.nlm.nih.gov/chemidplus/

bug 1406356 overlapping content following page-break-before in Firefox 56

bug 1427141 CSS page-break-before can cause elements to disappear in HTML tables

bug 1572573 Printing page with large table fails to display anything after the first page.

Printing: Setup

bug 1486968 Remove nsPrintJob::mOldPrtPreview

bug 1601589 Stop requiring MockWebBrowserPrint to store a PrintData object

bug 1601694 Remove the redundant Windows range/ifame selection code

bug 1601775 Stop needlessly calling PMPrintSettingsSetJobName in nsPrintDialogServiceX::Show

bug 1601800 Remove nsIPrintingPromptService.showPrintProgressDialog's nsIWebBrowserPrint parameter

bug 1602103 Set the print job name before initialization of the print session on macOS

bug 1602125 Remove nsIPrintingPromptService.showPrintDialog's nsIWebBrowserPrint parameter and MockWebBrowserPrint

bug 1604071 Dead assignment in nsPrintDialogServiceGTK::Show

SVG

bug 1598480 prefers-color-scheme media query does not update SVG images

bug 1599296 Image inside <svg:image> should not be draggable

bug 1600855 make SVGTextFrame avoid getting glyph advances that cross text frames, and re-enable letter/word-spacing

bug 1601824 InvalidArrayIndex_CRASH in [@ SVGTextFrame::DoTextPathLayout]