1395715 - stylo: Assertion failure: f (Must have found a first-line frame)

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect, P2)

Description

[Jesse Schwartzentruber (:truber)]

Attachment: testcase.html

The attached testcase raises an assertion in m-c rev 20170831-fb22415719a9 with stylo enabled by pref.

Assertion failure: f (Must have found a first-line frame), at /builds/worker/workspace/build/src/layout/base/ServoRestyleManager.cpp:1435

#0 mozilla::ServoRestyleManager::ReparentStyleContext, at layout/base/ServoRestyleManager.cpp:1435
#1 nsCSSFrameConstructor::RecoverLetterFrames, at layout/base/nsCSSFrameConstructor.cpp:12307
#2 nsCSSFrameConstructor::ContentRemoved, at layout/base/nsCSSFrameConstructor.cpp:8921
#3 mozilla::PresShell::ContentRemoved, at layout/base/PresShell.cpp:4512
#4 nsNodeUtils::ContentRemoved, at dom/base/nsNodeUtils.cpp:226
#5 nsINode::doRemoveChildAt, at dom/base/nsINode.cpp:1938
#6 mozilla::dom::FragmentOrElement::RemoveChildAt, at dom/base/FragmentOrElement.cpp:1369
#7 nsINode::ReplaceOrInsertBefore, at dom/base/nsINode.cpp:2250
#8 ConvertNodesOrStringsIntoNode, at dom/base/nsINode.h:1843
#9 nsINode::Before, at dom/base/nsINode.cpp:1783
#10 mozilla::dom::CharacterDataBinding::before, at dom/bindings/CharacterDataBinding.cpp:372
#11 mozilla::dom::GenericBindingMethod, at dom/bindings/BindingUtils.cpp:3050
#12 js::CallJSNative, at js/src/jscntxtinlines.h:293

Comment 1

[Boris Zbarsky [:bzbarsky]]

Attachment: When recovering letter frames, only do first-line fixup when we have a first-line parent

It turns out, this is the only case in which we need to do the fixup at all.
And this way we don't have to guess based on first-line styles, which may not
match the frame tree (for example if we have a pending style change that we
haven't processed yet).

Comment 2

[Boris Zbarsky [:bzbarsky]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=4d291c30a4a1e8f049fb9843379f3f34fe22091c is So Green.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/bc499bee82e2
When recovering letter frames, only do first-line fixup when we have a first-line parent.  r=emilio

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/bc499bee82e2