FULL PRODUCT VERSION :
java version "1.5.0_05"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_05-b05)
Java HotSpot(TM) Client VM (build 1.5.0_05-b05, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
ver Windows XP

A DESCRIPTION OF THE PROBLEM :
For text containing bidi text, pressing HOME at the end of a line goes to the beginning of next line.

I think it is a bug in the GlyphPainter2#getNextVisualPositionFrom function. For the case View.WEST, it just check if the character is '\n', but not checking if it is a space.

                        if(c == '\n') {
                            biasRet[0] = Position.Bias.Forward;
                            return endOffset - 1;
                        }

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1) Download the TextComponentDemo sample files from this link

http://java.sun.com/docs/books/tutorial/uiswing/components/generaltext.html

2) In the TextComponentDemo#initDocument() function,

Add the following lines before the for loop:

            doc.insertString (doc.getLength(), "It is a long paragraph for testing GlyphPainter2\n\n", attrs[0]);
            doc.insertString (doc.getLength(), "[\u062a\u0641\u0627\u062d}", attrs[0]);

3) Run the application
4) Click at the end of the first line. The status bar will show "caret: text position 35"
5) Press Home key. The caret goes to the beginning of the next line before "GlyphPainter2". The status bar also shows "caret: text position 35"
6) Now comment the line:
doc.insertString (doc.getLength(), "[\u062a\u0641\u0627\u062d}", attrs[0]);
7) Run the application again.
8) Click at the end of the first line. The status bar will show "caret: text position 34"
9) Press Home key. The caret goes to the beginning of the first line. The status bar also shows "caret: text position 0"

Notice when the text contains bidi text, clicking at the end of a line can position after the space character separting the line (i.e. position 35 in the above case). If there is no bidi text, the caret can only position after the last word of this line (i.e. position 34 in the above case).



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The caret should go to the beginning of the same line
ACTUAL -
The caret should go to the beginning of the next line

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
    protected void initDocument ()
    {
        String initString[] = { "Use the mouse to place the caret.",
                "Use the edit menu to cut, copy, paste, and select text.", "Also to undo and redo changes.",
                "Use the style menu to change the style of the text.",
                "Use these emacs key bindings to move the caret:", "ctrl-f, ctrl-b, ctrl-n, ctrl-p." };

        SimpleAttributeSet[] attrs = initAttributes (initString.length);

        try
        {
            int index = 0;
            
            // Add one of the following line
            doc.insertString (doc.getLength(), "It is a long paragraph for testing GlyphPainter2\n\n", attrs[0]);
            doc.insertString (doc.getLength(), "[\u062a\u0641\u0627\u062d}", attrs[0]);
            
            for (int i = 0; i < initString.length; i++)
            {
                index = doc.getLength ();
                doc.insertString (doc.getLength (), initString[i] + newline, attrs[i]);
            }
        }
        catch (BadLocationException ble)
        {
            System.err.println ("Couldn't insert initial text.");
        }
    }
---------- END SOURCE ----------