1379101 - Stylo: crash in geckoservo::glue::Servo_ResolveStyleLazily

Status: RESOLVED DUPLICATE of bug 1378814

(Core :: CSS Parsing and Computation, enhancement)

Description

[Julien Cristau [:jcristau]]

We got a few crashes since enabling the stylo build on windows, crashing in geckoservo::glue::Servo_ResolveStyleLazily from this expect():

                get_pseudo_style(
                    &guard,
                    element,
                    pseudo,
                    rule_inclusion,
                    styles,
                    /* inherited_styles = */ None,
                    &*data,
                    /* is_probe = */ false,
                ).expect("We're not probing, so we should always get a style \
                         back")

Comment 1

[Nicholas Nethercote [inactive]]

This is the #4 Windows topcrash in Nightly 20170707030206. Over the past 7 days there have been 18 crashes across 10 installations.

https://crash-stats.mozilla.com/report/index/4f8bc612-65c6-4959-93f4-fd2ce0170708 is an example crash.

The crash signature is a bit confusing. There are two problems.

- The "alloc::oom::default_oom_handler" makes it sound like an OOM, but I think that's not the case. The "core::option::expect_failed" makes it sound like an expect() call failed, and indeed stack frame 6 points to an |expect("We're not probing, so we should always get a style back")| call.

- The crash report doesn't include the expect() argument. It would be nice if it did.

Emilio, can you please take a look at the crash?

Ted, do you have any comments about the two problems I mentioned above?

Comment 2

[Hiroyuki Ikezoe (:hiro)]

I believe this is a dupe of bug 1378814.