The closed test javax/swing/text/ParagraphView/6423287/bug6423287.java
fails on Windows HiDPI at fractional scales.

The failure is
testMinimumSpan:
java.lang.RuntimeException: expected:<29.0> but was:<54.0>
at Assert.fail(Assert.java:13)
at Assert.failNotEquals(Assert.java:278)
at Assert.assertEquals(Assert.java:60)
at Assert.assertEquals(Assert.java:67)
at bug6423287.testMinimumSpan(bug6423287.java:93)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at TestCase.runTest(TestCase.java:80)
at TestCase.runAllTests(TestCase.java:53)
at bug6423287.main(bug6423287.java:24)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:1575)

at TestCase.runAllTests(TestCase.java:69)
at bug6423287.main(bug6423287.java:24)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:1575)

There are a number of sub-tests but a simple reproducer for the specific failure is attached as Span.java
It isn't immediately obvious what the problem is but since it fails at 150% and not at 200%, and the delta of 29 to 54 is clearly huge, it is possible something like a rounding error causes a completely wrong calculation.