Invalid redirection to issue after screenshot attachment

In General configuration, Base URL is "http://jiraeti.mycompany.ch/jira"

I open a ticket from URL: http://jiraeti.mycompany.ch/jira/browse/TESTPROJECT-79

After screenshot insertion with "Attach" button in the applet,
the browser is redirected to http://jiraeti.mycompany.ch/browse/TESTPROJECT-79
and of course it fails with a 404.

By the way, the screenshot is properly attached to the issue.

As standalone package use "ROOT", the problem does not appear as redirection is
valid. When deployed in a non-root context path, redirection is invalid.

Please fix the redirection after attachment and describe files to patch on my JIRA 4.2.1 setup.
Thank you in advance.