1.439 to 1.563 is a pretty big jump!

Could you try 1.560 to see whether the issue occurs there as well? There was a change related to a newly integrated version of CodeMirror (https://github.com/jenkinsci/jenkins/commit/5789f0c75c3782f5c58d594ccced90428712ecdf).

Other than that, it'd help if you could do a "binary" search to narrow down the version range (or at least explain how to reproduce the issue).

Actually, you are right.
I downloaded the 1.549 version of jenkins at http://jenkins.mirror.isppower.de/war/1.549/jenkins.war and tested it on my local machine which is running on Windows.
I can't reproduce this issue with it.

So I'm explaining how to reproduce this issue with a >= 1.560 version of jenkins but my englsih is quite bad and hope that you are understanding :

• If you're running on windows Download and install the screen reader NVDA at www.nvaccess.org (it is free)
• During the installation you should ear a voice. This voice says what you see on the screen.
• Complete the installation
• Run a browser in example firefox (fhe latest version 29.0.1)
• Go to the board of your jenkins and choose a job which has a shell script step configured
• In the job page, click on "configure" to edit the job
  NB: In the next step, you should know that NVDA has a virtual buffer to represent a web content and provides shortcuts to navigate through the elements of a web page.
  In example, to go to the next edit field, you should type 'e', the next button 'b' radio button 'r' ... and shift + e to go to previous edit field ...
  To read and edit the content of an element like an edit field, you must hit the space bar to enter in.
• With the shortcut 'e', navigate until NVDA says 'edit multiline'. If the rate of the voice is too fast, decrase it with (NVDA key + CTRL + the right and left arrow keys to select "rate" setting and decrease it with the down arrow key. The NVDA key is the 0 of your numeric pad.
• As explained below, to read and edit the shell script you should type on the space bar.
• Then, with the up and down arrow key, you should ear the lines of the shell script. With left and right arrow key you navigate character by character.

In jenkins 1.563 I can navigate through the differents lines of my shell script so I can't edit it.

I really hope that you understand me .

Thanks in advance.

It seems very likely that the hotfix of JENKINS-23151 (in 1.567) would solve this issue for you. I am guessing that the authors of CodeMirror simply never considered the effect on accessibility. Internally it seems to hide the original textarea and then use JavaScript to insert a new page area with the colored text with special behavior. In other words, it is quite different than a styled text area in, say, (Java) Swing, which follows the same data model as a plain text area but adds style annotations. In that case the question is whether CodeMirror can be used at all, for anything in Jenkins.

1.567 has been released. Guillaume, could you try it?

Also, could you try whether the same issue occurs for descriptions of build parameters? Freestyle project, 'This build (sic) is parameterized', add a parameter, and edit its description. May depend on your markup formatter configured in the security configuration though.