RFR [S] 6854417: TESTBUG: java/util/regex/RegExTest.java fails intermittently

[Ivan Gerasimov]

Hello!

RegExTest fails sometimes in checking Boyer-Moore search.
This is because it was assumed that after insertion a pattern into a 
string at some position, we'll find it at the same position.
That's not true if we insert 'aa' into 'xxaxx' at index 3, cause then 
we'll find 'aa' at index 2.

The proposed fix is to exclude patterns that start and end with the same 
substring, because only those can cause this kind of problem.

Would you please help review the fix?

BUGURL: https://bugs.openjdk.java.net/browse/JDK-6854417
WEBREV: http://cr.openjdk.java.net/~igerasim/6854417/00/webrev/

Sincerely yours,
Ivan