This bug is for crash report bp-bc75b5e9-9a69-441f-8e20-9315c0200525.

Top 10 frames of crashing thread:

0 mozglue.dll mozalloc_abort memory/mozalloc/mozalloc_abort.cpp:33
1 mozglue.dll mozalloc_handle_oom memory/mozalloc/mozalloc_oom.cpp:51
2 xul.dll gkrust_shared::oom_hook::hook toolkit/library/rust/shared/lib.rs:221
3 xul.dll std::alloc::rust_oom ../4fb7144ed159f94491249e86d5bbd033b5d60550//src/libstd/alloc.rs:240
4 xul.dll mozilla::wr::ShmSegmentsReader::GetReadPointerOrCopy gfx/layers/wr/IpcResourceUpdateQueue.h:84
5 xul.dll webrender_bindings::bindings::wr_vec_u8_reserve gfx/webrender_bindings/src/bindings.rs:293
6 xul.dll mozilla::layers::WebRenderBridgeParent::UpdateResources gfx/layers/wr/WebRenderBridgeParent.cpp:587
7 xul.dll mozilla::layers::WebRenderBridgeParent::RecvUpdateResources gfx/layers/wr/WebRenderBridgeParent.cpp:846
8 xul.dll mozilla::layers::PWebRenderBridgeParent::OnMessageReceived ipc/ipdl/PWebRenderBridgeParent.cpp:624
9 xul.dll mozilla::layers::PCompositorManagerParent::OnMessageReceived ipc/ipdl/PCompositorManagerParent.cpp:197

There is 1 crash in nightly 78 with buildid 20200525093440. In analyzing the backtrace, the regression may have been introduced by patch [1] to fix bug 1639563.

[1] https://hg.mozilla.org/mozilla-central/rev?node=adde6fa9b4d6

It's possible that bug 1639563 caused this, either just via the increased memory from from font sanitization, or the Vec capacity bug I had accidentally incorporated into the original patch. I think I addressed that issue in a follow-up inside bug 1639563.

Never the less, it is also conceivable we might see a slight spike in this due to the increased memory load for font sanitization.

I am marking this as a low priority bug right now until or if we see enough of a spike in crashes to discern that this is actually a problem. For now we seem to be holding steady.

Closing because no crashes reported for 12 weeks.