The subversion plugin always checkouts broken symbolic links(whose target file is missing) as normal text files with the content of "link target-file-name", no matter which SVN version is selected(from 1.4 to 1.8). Meanwhile, it's OK to check out complete symbolic links(whose target file exists).
Manually checking out (out of jenkins) using host's SVN(version 1.9) is OK for all symbolic links.
Please be noted that this is not the bug of
JENKINS-3904 .I can still checkout out complete symbolic links.