FULL PRODUCT VERSION :
java version "1.8.0_40"
Java(TM) SE Runtime Environment (build 1.8.0_40-b26)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Linux mag.ca.com 2.6.32-504.23.4.el6.x86_64 #1 SMP Fri May 29 10:16:43 EDT 2015 x86_64 x86_64 x86_64 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
The following code fails on JDK 8 but works fine on JDK 7

Pattern p = Pattern.compile("^(.{\\Q8\\E})");

On JDK 8, the regex compilation fails with the following stack trace:

Exception in thread "main" java.util.regex.PatternSyntaxException: Illegal repetition near index 2
^(.{\Q8\E})
  ^
at java.util.regex.Pattern.error(Pattern.java:1955)
at java.util.regex.Pattern.closure(Pattern.java:3157)
at java.util.regex.Pattern.sequence(Pattern.java:2134)
at java.util.regex.Pattern.expr(Pattern.java:1996)
at java.util.regex.Pattern.group0(Pattern.java:2905)
at java.util.regex.Pattern.sequence(Pattern.java:2051)
at java.util.regex.Pattern.expr(Pattern.java:1996)
at java.util.regex.Pattern.compile(Pattern.java:1696)
at java.util.regex.Pattern.<init>(Pattern.java:1351)
at java.util.regex.Pattern.compile(Pattern.java:1028)
at com.ca.samples.esales.TestJava.main(TestJava.java:11)

REGRESSION. Last worked in version 7u80

ADDITIONAL REGRESSION INFORMATION:
This issue is not seen in JDK 7.

I tried both Oracle and OpenJDK and see the issue in both distributions.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile and Run the following program in JRE 8 -

public class TestJava {

public static void main(String[] args) {
// TODO Auto-generated method stub


Pattern p = Pattern.compile("^(.{\\Q8\\E})");
System.out.println(p.toString());

}

}

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The program must print the compiled regex pattern.
ACTUAL -
On JDK 8, the regex compilation fails with the following stack trace:

Exception in thread "main" java.util.regex.PatternSyntaxException: Illegal repetition near index 2
^(.{\Q8\E})
  ^
at java.util.regex.Pattern.error(Pattern.java:1955)
at java.util.regex.Pattern.closure(Pattern.java:3157)
at java.util.regex.Pattern.sequence(Pattern.java:2134)
at java.util.regex.Pattern.expr(Pattern.java:1996)
at java.util.regex.Pattern.group0(Pattern.java:2905)
at java.util.regex.Pattern.sequence(Pattern.java:2051)
at java.util.regex.Pattern.expr(Pattern.java:1996)
at java.util.regex.Pattern.compile(Pattern.java:1696)
at java.util.regex.Pattern.<init>(Pattern.java:1351)
at java.util.regex.Pattern.compile(Pattern.java:1028)
at com.ca.samples.esales.TestJava.main(TestJava.java:11)

ERROR MESSAGES/STACK TRACES THAT OCCUR :
On JDK 8, the regex compilation fails with the following stack trace:

Exception in thread "main" java.util.regex.PatternSyntaxException: Illegal repetition near index 2
^(.{\Q8\E})
  ^
at java.util.regex.Pattern.error(Pattern.java:1955)
at java.util.regex.Pattern.closure(Pattern.java:3157)
at java.util.regex.Pattern.sequence(Pattern.java:2134)
at java.util.regex.Pattern.expr(Pattern.java:1996)
at java.util.regex.Pattern.group0(Pattern.java:2905)
at java.util.regex.Pattern.sequence(Pattern.java:2051)
at java.util.regex.Pattern.expr(Pattern.java:1996)
at java.util.regex.Pattern.compile(Pattern.java:1696)
at java.util.regex.Pattern.<init>(Pattern.java:1351)
at java.util.regex.Pattern.compile(Pattern.java:1028)
at com.ca.samples.esales.TestJava.main(TestJava.java:11)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.regex.Pattern;

public class TestJava {

public static void main(String[] args) {
// TODO Auto-generated method stub


Pattern p = Pattern.compile("^(.{\\Q8\\E})");
System.out.println(p.toString());

}

}
---------- END SOURCE ----------