java/awt/font/GlyphVector/TestLayoutFlags.java now looks for a font
that supports the code points and makeGlyphVector returns null if
none is found. But there is no code in test(..) to skip + return in that case.
So if this happens to be run on a system without such fonts we can get
an NPE like this:
Using Bitstream Charter for script latin
No font found for script hebrew
No font found for script arabic
No font found for script devanagari
No font found for script tamil

*** latin ***
 test flags
computed flags: pos
  actual flags: pos
allowed layout flags: none
----------System.err:(17/986)----------
java.lang.NullPointerException
at TestLayoutFlags.validateCharIndexMethods(TestLayoutFlags.java:225)
at TestLayoutFlags.computeFlags(TestLayoutFlags.java:204)
at TestLayoutFlags.test(TestLayoutFlags.java:146)
at TestLayoutFlags.runTest(TestLayoutFlags.java:88)
at TestLayoutFlags.main(TestLayoutFlags.java:42)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:569)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:832)

JavaTest Message: Test threw exception: java.lang.NullPointerException
JavaTest Message: shutting down test
====

The fix is just to add that check.