108866 - Blank bar through images on pages with Java applets

Status: RESOLVED DUPLICATE of bug 93170

(Core Graveyard :: Java: OJI, defect)

Description

[mozilla]

From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows 98)(A Macintosh OS X bug 
reported using a windows computer)
BuildID:    20011022 with MRJPlugin 1.0d5

   As illustrated at http://segal.org/blankbar/index.html there is a display 
problem in Netscape 6.2 for Macintosh OS 10.1 (Mozilla 20011022 with MRJPlugin 
1.0d5). A blank bar appears in the image, covering part of the "m" 
in "Rheumatology". 

Reproducible: Sometimes
Steps to Reproduce:
1. Make sure the MRJPlugin is installed.
2. Go to http://segal.org/blankbar/index.html


Actual Results:  A blank bar appears in the image, covering part of the "m" 
in "Rheumatology".  This happens about a third of the time.  This behavior 
seems to be more frequent when the mouse is being moved, or the mouse is over 
the browser pane (as opposed to the mouse being over the browser's "Reload" 
button). 

Expected Results:  No blank bar.

    This bar through images seems to depend on a Java applet being on the same 
page as the image.  This does not appear to be a problem with a specific Java 
applet since the problem has been seen with three different Java applets (but 
the Java source code for this particular applet is supplied below).  The 
problem does not appear to be a problem with this particular image since it has 
been seen also with a different image, which also gets a blank bar down its 
center.  If the image is in a different position on the page the blank bar is 
still down the center of the image.

    It is not clear whether there is something special about Java applets that 
results in this problem or whether the problem arises from the delay required 
to load a Java applet.  

    The problem does not occur with Netscape for Macintosh OS 9 or Internet 
Explorer 5.1.2 for OS 10.1. 

    Rarely, a second problem has been seen with this page, consisting of a 
second copy of one of the applet buttons appearing in another location such as 
covering the address bar of the browser.  This is reminiscent of the TextField 
Display Bug (http://bugzilla.mozilla.org/show_bug.cgi?id=108019).

Source code for the applet:
import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class ConfusedComponents extends Applet implements ActionListener {
Choice choice;
Button buttonThis, buttonThat;
PopupMenu myPopup;
MenuItem[] menuItem;

public void init() 
{
    buttonThis = new Button("Click this button");
    buttonThis.addActionListener(this);
    add(buttonThis); 
    buttonThat = new Button("Don't click this button");
    add(buttonThat);
    choice = new Choice();
    choice.addItem("Choice line 1 ");
    choice.addItem("Choice line 2 ");
    add(choice);
    myPopup = new PopupMenu();
    menuItem = new MenuItem[2];
    for (int i=0; i < 2; i++)
    {
        myPopup.addSeparator();
        menuItem[i] = new MenuItem("Menuitem " + String.valueOf(i+1));
        myPopup.add(menuItem[i]);
    }
    add(myPopup);
}

public void actionPerformed(ActionEvent ae)
{
    if (ae.getSource() == buttonThis) myPopup.show(buttonThat, 10, 10);
}
} // END OF Class ConfusedComponents

Comment 1

[Chris Petersen]

Confirming issue on the Nov 08 Mac OS X build.

Comment 2

[Chris Petersen]

I believe this issue is related to
http://bugzilla.mozilla.org/show_bug.cgi?id=93170.

That problem is certain Gif images are not being properly painted when a
QT/flash  object is on the page. The workaround is set monitor to thousands,
then the problem is corrected. If you this same procedure with the specified
test case, it resolves ths problem.

Comment 3

[mozilla]

I confirm that in Thousands of colors this bug does not appear.  Incidently, 
when the color resolution is changed the browser pane and controls do not 
repaint; they only repaint after maneuvers such as resizing the browser.

Comment 4

[Patrick C. Beard]

This is a general plugins problem. I believe this is a duplicate of a known 
plugin bug.

Comment 5

[Peter Lubczynski]

*** This bug has been marked as a duplicate of 93170 ***