Product version: JDK9b100

REPRODUCIBILITY :
This bug can be reproduced always in JDK9b100.
This bug can not be reproduced in JDK8u66-b18.

The test case is to verify Month.getDisplayName() with different TextStyle and different provider on different locale. It failed when specifying "-Djava.locale.providers=JRE" and TextStyle to "NARROW" and "NARROW_STANDALONE" on de, de_DE, en_US, tr_TR locale. I wrote a sample code to reproduce this issue, please refer to attachment MonthTest.java.

Expect result:
Output should be same with running on JDK8. Please refer to attachment jdk8u66b18.txt.

Actual result:
On en_US, de, de_DE locale, output of narrow month name is a digit.
On tr_TR locale, output of narrow and standalone narrow month name is a digit.
Please refer to attachment jdk9b100.txt.

How to reproduce:
Run attachment sample code MonthTest.java:
java -Djava.locale.providers=JRE MonthTest