FULL PRODUCT VERSION :
java version "1.7.0-ea"
Java(TM) SE Runtime Environment (build 1.7.0-ea-b107)
Java HotSpot(TM) 64-Bit Server VM (build 19.0-b05, mixed mode)

Also reproduced under JDK 1.6. There is no such problem in JDK 1.5

ADDITIONAL OS VERSION INFORMATION :
Linux home 2.6.31-22-generic #63-Ubuntu SMP Thu Aug 19 00:23:50 UTC 2010 x86_64 GNU/Linux
Darwin home 10.4.1 Darwin Kernel Version 10.4.1: Wed May 12 21:36:54 PDT 2010; root:xnu-1504.7.50~2/RELEASE_I386 i386


A DESCRIPTION OF THE PROBLEM :
JEditorPane shows text with LTR/RTL embedding chars(\u202a,\u202b,\202c) much slower. Even if LTR-only chars emedded in LTR component.



JDK 1.5 doesn't have this problem

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Just add text with LTR/RTL embedded chars into JEditorPane

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expected performance like in JDK 1.5, or without LTR/RTL embedded chars.
ACTUAL -
JDK 1.7,1.6 require less than one second for display the same text without LTR/RTL embeding chars, but with these chars it required:
~11 seconds on JDK 1.7 and JDK 1.6 on Linux
~38 seconds on JDK 1.6 on Apple's Mac Mini

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.*;

public class test {
    public static void main(String[] args) throws Exception {

        StringBuilder text = new StringBuilder();
        for (int i = 0; i < 10000; i++) {
            text.append("\u202a this is test for embedded LTR/RTL \u202c\n");
        }

        JFrame f = new JFrame();

        final JEditorPane e = new JEditorPane();

        long st = System.currentTimeMillis();
        e.setText(text.toString());
        long en = System.currentTimeMillis();
        System.out.println("Time=" + (en - st) + "ms");

        f.setContentPane(e);
        f.pack();
        f.setSize(800, 700);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        f.setVisible(true);
    }
}

---------- END SOURCE ----------