Description:

Helo.

There is a strange problem when I load a big enough file in any Java Swing app, say NetBeans or Oracle SQL Developper. The "big enough" thing is around 2200 and 2300 lines and it must contain accented letters. In that case, the scrolling of the start of the file is done in a way that maekes the text completely unreadable. It's as if the new page were drawn without erasing the previews, so it is always overdrawn.

I made a test program that creates a string of random length, with only the 'á' character. It also behaves like that when the number of lines is bigger than 2300 lines, more or less. It is attached for anyone that wants to try.

Steps to reproduce:

1. Download the attachment
2. Compile it with javac TesteTamanho.java (it means LenghtTest - sory for the names, I'm from Brazil, so the program is in portuguese)
3. Run it with java TesteTamanho
4. Click the button named Aleatório (it means Random)
5. The program will show the number of lines generated
6. Go to the start of the text and scroll either with Page Down, Page Up or the scroll bar.
7. The text will be messed up if the number of lines is bigger then 2300, more or less.

I proposed this test in the brazilian Archlinux discussion list and some people reported that it realy happens. One interesting fact is that one user said he had this same problem when using the xf86-video-intel driver. He solved it using the obsolete xf86-video-i810 driver. And another user, who runned the test with a intel driver, said he solved it with the sugestion to change to the i810 driver.

I tried to change to i810 but it didn't work with my xorg.conf. I rely on autodetection, so I will need to update the file to make it work, so it will take some time to test it. But the test worked well (no redraw problems) in an Ubuntu 8.04, with intel driver version 2.2.1.

I will test this in my home desktop, with an nvidia card. It is not update for sometime (since kde4 hitted extra).

Additional info:
* package version(s): tested with jdk/jre 1.6.0.06, 1.6.0.10 and openjdk 1.6.0. Tested with Sun's binary 1.5.0.16 (also have problems). Tested intel driver in testing and in extra repositories.

PS: the attached file was made using NetBeans visual editor, so it has some ugly code for generating the user interface. But the test is very simple.