Just noting that the behavior is the same on Macs as well.

Bisected to r603037 "Roll HarfBuzz to contain emoji cluster formation"
Landed in 72.0.3593.0
Merged to 71.0.3578.28

Able to reproduce the issue on reported version# 71.0.3578.98 and on latest chrome# 73.0.3651.0 using Windows-10 and Ubuntu 17.10 hence providing Bisect Info
Note: Issue is not seen on Mac 10.12.6

Bisect Info:
================
Good build: 71.0.3578.27
Bad build: 71.0.3578.28

As the issue break is seen in 71.0.3578 branch builds, hence providing below change-log from omahaproxy
Change-Log: https://chromium.googlesource.com/chromium/src/+log/71.0.3578.27..71.0.3578.28?pretty=fuller&n=10000
Suspecting: https://chromium.googlesource.com/chromium/src/+/746156f503ddf75d5037574c27889eb0030e37f6 from above change log
Change-Id: I34d22a48ec8e4a9a627b12c68efefaabdcd015c7
Reviewed-on: https://chromium-review.googlesource.com/c/1264519

@Dominik Röttsches: Please confirm the issue and help in re-assigning if it is not related to your change.
Adding ReleaseBlock-Stable for M-71, feel free to remove it if not applicable.

Thanks!

Let's target 72/73 for this. 

Reported as https://github.com/harfbuzz/harfbuzz/issues/1516

Affected by HarfBuzz commit:
https://github.com/harfbuzz/harfbuzz/commit/df32eaae42b505b00de4a8b5efce9ab948bed847

As noted in https://github.com/harfbuzz/harfbuzz/issues/1516#issuecomment-450181694, these are sequences that according to Unicode should *not* be used; there are separately-encoded atomic characters that should be used instead. See table 12-16 in the Unicode standard.

This issue is marked as a release blocker with no milestone associated. Please add an appropriate milestone.

All release blocking issues should have milestones associated to it, so that the issue can tracked and the fixes can be pushed promptly.

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This issue is marked as a release blocker with no milestone associated. Please add an appropriate milestone.

All release blocking issues should have milestones associated to it, so that the issue can tracked and the fixes can be pushed promptly.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Closing as WontFix as discussed in https://github.com/harfbuzz/harfbuzz/issues/1516 - Unicode recommends not using the first of the two mentioned sequences. Table 12-16 in http://www.unicode.org/versions/Unicode11.0.0/ch12.pdf has the recommended encodings. We follow this recommendation in that we insert dotted circle characters when the invalid encodings are used, as do other implementations such as Word and WordPad on Windows and others. 

If the reporter objects to those recommendations, the issue should be raised with the Unicode consortium or in Unicode mailing list.

The NextAction date has arrived: 2019-01-03