xorg-server @1.20.5: screen capture of java programs from ubuntu server are missing visual components

[amkearns-usgs]

Using Ubuntu LTS 18.04.2, xorg-server displays java applications correctly but fails to properly render saved screenshots of these applications, causing some outlines and GUI data to be lost when doing a screen capture. This issue occurs when color depth is set to values greater than 256; when set at 256 color the programs render their screenshots correctly, but sometimes have their fonts rendered in a way that the programs are nearly unusable, and as a result this is not a suitable workaround.

In the attached images the screen capture of the program running under Ubuntu has a terminal window with transparency increased placed over it. In places where the image capture utility must render images with alpha components, the otherwise-missing GUI components become visible underneath them.

The expected output has a timestamp in the file of 4.43.29 PM and the received outputs are stamped at 4.46.36 (with the terminal overlay showing the missing GUI components behind it) and 6.05.00.

This is only an issue for screen captures. The windows render correctly on the display.

This issue does not occur on Windows clients connecting to the server with their x11 server applications.

Prior to Ubuntu our servers were using Scientific Linux 6, which did not have this issue. However, using xorg-server (or XQuartz) with Scientific Linux 7 and Ubuntu both share this issue. We are not certain of what configurations on the server would have changed in the process of upgrading that would affect this, but we are also not sure why only Mac connections to the server are affected by this.

The program we have taken these screenshots of is available on github to test with, should that be of interest: ​https://github.com/usgs/xmax

[amkearns-usgs]

Screenshots of expected and received image capture of relevant java program