content_length.patch

diff --git a/src/jobs.js b/src/jobs.js
index 6ea979e..fbbed59 100644
--- a/src/jobs.js
+++ b/src/jobs.js
@@ -554,7 +554,11 @@ exports.initApp = function(app) {
             if (groupsModule.canAccessJob(req.user, dbjob)) {
                 let jobdir = _getJobDir(dbjob)
                 res.status(200).type('tar.gz')
-                tar.pack(jobdir).pipe(zlib.createGzip()).pipe(res)
+                tar.pack(jobdir, {
+                    map: function(header) {
+                        res.set('Content-Length', header.size)
+                    },
+                }).pipe(zlib.createGzip()).pipe(res)
             } else {
                 res.status(403).send()
             }