When I run Mozilla's automated tests on a gcc fsanitize=enum build,the following runtime error: Here is the stack trace: [task 2017-09-30T01:38:24.282Z] 01:38:24 INFO - /builds/worker/workspace/build/src/layout/base/PresShell.cpp:6828:21: runtime error: load of value 4287326164, which is not a valid value for type 'nsEventStatus'^M [task 2017-09-30T01:38:24.284Z] 01:38:24 INFO - #0 0xf0b27b72 in mozilla::PresShell::HandleEvent(nsIFrame*, mozilla::WidgetG\ UIEvent*, bool, nsEventStatus*, nsIContent**) (/builds/worker/workspace/build/application/firefox/libxul.so+0x25f8b72)^M [task 2017-09-30T01:38:24.285Z] 01:38:24 INFO - #1 0xf08a643b in nsViewManager::DispatchEvent(mozilla::WidgetGUIEvent*, nsVi\ ew*, nsEventStatus*) (/builds/worker/workspace/build/application/firefox/libxul.so+0x237743b)^M [task 2017-09-30T01:38:24.286Z] 01:38:24 INFO - #2 0xf0b015df in mozilla::PresShell::DispatchSynthMouseMove(mozilla::WidgetG\ UIEvent*, bool) (/builds/worker/workspace/build/application/firefox/libxul.so+0x25d25df)^M [task 2017-09-30T01:38:24.287Z] 01:38:24 INFO - #3 0xf0b0bd76 in mozilla::PresShell::ProcessSynthMouseMoveEvent(bool) (/buil\ ds/worker/workspace/build/application/firefox/libxul.so+0x25dcd76)^M [task 2017-09-30T01:38:24.288Z] 01:38:24 INFO - #4 0xf0b22f7a in mozilla::PresShell::nsSynthMouseMoveEvent::WillRefresh(mozi\ lla::TimeStamp) (/builds/worker/workspace/build/application/firefox/libxul.so+0x25f3f7a)^M [task 2017-09-30T01:38:24.289Z] 01:38:24 INFO - #5 0xf0aed684 in nsRefreshDriver::Tick(long long, mozilla::TimeStamp) (/buil\ ds/worker/workspace/build/application/firefox/libxul.so+0x25be684)^M [task 2017-09-30T01:38:24.290Z] 01:38:24 INFO - #6 0xf0aeecbc in mozilla::RefreshDriverTimer::TickRefreshDrivers(long long, \ mozilla::TimeStamp, nsTArray<RefPtr<nsRefreshDriver> >&) (/builds/worker/workspace/build/application/firefox/libxul.so+0x25bfcbc)^M [task 2017-09-30T01:38:24.291Z] 01:38:24 INFO - #7 0xf0aeedc6 in mozilla::RefreshDriverTimer::Tick(long long, mozilla::TimeS\ tamp) (/builds/worker/workspace/build/application/firefox/libxul.so+0x25bfdc6)^M [task 2017-09-30T01:38:24.293Z] 01:38:24 INFO - #8 0xf0aeefd1 in mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserve\ r::TickRefreshDriver(mozilla::TimeStamp) (/builds/worker/workspace/build/application/firefox/libxul.so+0x25bffd1)^M [task 2017-09-30T01:38:24.293Z] 01:38:24 INFO - #9 0xf0aef22f in mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserve\ r::NotifyVsync(mozilla::TimeStamp) (/builds/worker/workspace/build/application/firefox/libxul.so+0x25c022f)^M

Hi -- unfortunately I'm not sure if I should be using nsEventStatus_eIgnore or nsEventStatus_eConsumeNoDefault here.

I meant to say: I'm not sure if I should be using nsEventStatus_eIgnore or nsEventStatus_eConsumeDoDefault here.

Thanks for the review.

Pushed by ryanvm@gmail.com: https://hg.mozilla.org/integration/autoland/rev/45eb821ac9d5 Fix ubsan runtime error for nsEventStatus enum in PresShell.cpp. r=smaug