File f = writeTrashFile("symlink", "content");
Git git = new Git(db);
db.getConfig().setString(ConfigConstants.CONFIG_CORE_SECTION, null,
ConfigConstants.CONFIG_KEY_SYMLINKS, "false");
git.add().addFilepattern("symlink").call();
git.commit().setMessage("commit").call();
// Modify previously committed DirCacheEntry and write it back to disk
DirCacheEntry dce = db.readDirCache().getEntry("symlink");
dce.setFileMode(FileMode.SYMLINK);
DirCacheCheckout.checkoutEntry(db, f, dce);