Bugzilla

Testcase found while fuzzing mozilla-central rev 4d62ab0e31fd.

Hit MOZ_CRASH(called `Option::unwrap()` on a `None` value) at src/libcore/option.rs:355

```
rax = 0x000055c53b062e40   rdx = 0x0000000000000000
rcx = 0x0000000000000b40   rbx = 0x00007fb9430f3f1a
rsi = 0x00007fb9703af8b0   rdi = 0x00007fb9703ae680
rbp = 0x00007fb9430f3f00   rsp = 0x00007fb9430f3ef0
r8 = 0x00007fb9703af8b0    r9 = 0x00007fb9430fd700
r10 = 0x0000000000000000   r11 = 0x0000000000000000
r12 = 0x0000000000000163   r13 = 0x0000000000000015
r14 = 0x00007fb93a603ca0   r15 = 0x000000000000002b
rip = 0x00007fb962aa06c3
OS|Linux|0.0.0 Linux 4.18.0-16-generic #17~18.04.1-Ubuntu SMP Tue Feb 12 13:35:51 UTC 2019 x86_64
CPU|amd64|family 6 model 94 stepping 3|1
GPU|||
Crash|SIGSEGV /SEGV_MAPERR|0x0|51
51|0|libxul.so|GeckoCrash|hg:hg.mozilla.org/mozilla-central:mfbt/Assertions.h:4d62ab0e31fd6918ca95763914a8bdf41afe757a|314|0x0
51|1|libxul.so|gkrust_shared::panic_hook|hg:hg.mozilla.org/mozilla-central:toolkit/library/rust/shared/lib.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|234|0x9
51|2|libxul.so|core::ops::function::Fn::call|git:github.com/rust-lang/rust:src/libcore/ops/function.rs:9fda7c2237db910e41d6a712e9a2139b352e558b|78|0x5
51|3|libxul.so|std::panicking::rust_panic_with_hook|git:github.com/rust-lang/rust:src/libstd/panicking.rs:9fda7c2237db910e41d6a712e9a2139b352e558b|495|0x6
51|4|libxul.so|std::panicking::continue_panic_fmt|git:github.com/rust-lang/rust:src/libstd/panicking.rs:9fda7c2237db910e41d6a712e9a2139b352e558b|398|0x18
51|5|libxul.so|rust_begin_unwind|git:github.com/rust-lang/rust:src/libstd/panicking.rs:9fda7c2237db910e41d6a712e9a2139b352e558b|325|0x5
51|6|libxul.so|core::panicking::panic_fmt|git:github.com/rust-lang/rust:src/libcore/panicking.rs:9fda7c2237db910e41d6a712e9a2139b352e558b|95|0x6
51|7|libxul.so|core::panicking::panic|git:github.com/rust-lang/rust:src/libcore/panicking.rs:9fda7c2237db910e41d6a712e9a2139b352e558b|59|0x6
51|8|libxul.so|<webrender::prim_store::SpaceMapper<F, T>>::map|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/util.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|0|0xd
51|9|libxul.so|webrender::picture::PictureUpdateState::update|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/picture.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|2771|0x11
51|10|libxul.so|webrender::picture::PictureUpdateState::update|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/picture.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|1722|0x1f
51|11|libxul.so|webrender::picture::PictureUpdateState::update|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/picture.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|1722|0x1f
51|12|libxul.so|webrender::picture::PictureUpdateState::update|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/picture.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|1722|0x1f
51|13|libxul.so|webrender::picture::PictureUpdateState::update|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/picture.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|1722|0x1f
51|14|libxul.so|webrender::picture::PictureUpdateState::update_all|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/picture.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|1636|0x20
51|15|libxul.so|webrender::frame_builder::FrameBuilder::build|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/frame_builder.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|378|0x10
51|16|libxul.so|webrender::render_backend::Document::build_frame|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/render_backend.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|509|0x3f
51|17|libxul.so|webrender::render_backend::RenderBackend::update_document|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/render_backend.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|1372|0xe
51|18|libxul.so|webrender::render_backend::RenderBackend::process_api_msg|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/render_backend.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|1248|0x36
51|19|libxul.so|webrender::render_backend::RenderBackend::run|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/render_backend.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|934|0x1d
51|20|libxul.so|std::sys_common::backtrace::__rust_begin_short_backtrace|hg:hg.mozilla.org/mozilla-central:gfx/wr/webrender/src/renderer.rs:4d62ab0e31fd6918ca95763914a8bdf41afe757a|2054|0x8
51|21|libxul.so|mozilla::wr::WebRenderMallocEnclosingSizeOf|hg:hg.mozilla.org/mozilla-central:gfx/webrender_bindings/WebRenderAPI.cpp:4d62ab0e31fd6918ca95763914a8bdf41afe757a|31|0x16
51|22|libxul.so|std::__detail::_Hashtable_alloc<std::allocator<std::__detail::_Hash_node<std::pair<unsigned long const, mozilla::wr::WrSpaceAndClip>, false> > >::_M_allocate_buckets(unsigned long)|hg:hg.mozilla.org/mozilla-central:gcc/include/c++/6.4.0/bits/hashtable_policy.h:4d62ab0e31fd6918ca95763914a8bdf41afe757a|1998|0x7
51|23|||||0x7fb943573290
51|24|libxul.so|_fini|||0x2a372dc
51|25|libxul.so|_fini|||0x2a3719c
51|26|libxul.so|_fini|||0x2a36f94
51|27|libGLX.so.0.0.0||||0x6001
51|28|libGLdispatch.so.0.0.0||||0x425e0
```