Needed to work around a bug introduced in 10.13.3.
Created attachment 337897 [details] Patch
<rdar://problem/39188082>
Created attachment 337898 [details] Patch
Comment on attachment 337898 [details] Patch OK, let's try that as a temporary workaround.
Created attachment 337900 [details] Patch for landing
Comment on attachment 337900 [details] Patch for landing Clearing flags on attachment: 337900 Committed r230641: <https://trac.webkit.org/changeset/230641>
All reviewed patches have been landed. Closing bug.
<rdar://problem/39417564>