filer panic

[qszxnp]

Describe the bug
filer panic after "timed deletion"
from the filer log snapshot, i know that the line cause panic is :
/home/travis/gopath/src/github.com/chrislusf/seaweedfs/weed/operation/delete_content.go:98 +0x1ec
it is just a simple append:
ret = append(ret, deleteResults...)
is it the golang gc cause the panic?

System Setup

• List the command line to start "weed master", "weed volume", "weed filer", "weed s3", "weed mount".
  weed -v 100 -logdir=/data/seaweedfs/log/filer filer -ip 0.0.0.0 -master 172.18.16.22:9333,172.18.16.23:9333,172.18.16.24:9333
  weed -logdir=/data/seaweedfs/log master -ip 172.18.16.22 -peers 172.18.16.23:9333,172.18.16.24:9333 -mdir /data/seaweedfs/meta
  weed -logdir=/data/seaweedfs/log/v_18080 volume -dir=/data02/seaweefs/ -max=50 -mserver=172.18.16.22:9333,172.18.16.23:9333,172.18.16.24:9333 -port=18080 -rack rc1 -publicUrl 172.18.16.22 -ip 172.18.16.22
  weed -logdir=/data/seaweedfs/log/v_18081 volume -dir=/data03/seaweefs/ -max=50 -mserver=172.18.16.22:9333,172.18.16.23:9333,172.18.16.24:9333 -port=18081 -rack rc1 -publicUrl 172.18.16.22 -ip 172.18.16.22

• OS version
  CentOS Linux release 7.6.1810 (Core)

• output of weed version
  version 1.24 linux amd64

• if using filer, show the content of filer.toml
  [root@bogon seaweedfs]# cat filer.toml
  [redis]
  enabled = true
  address = "172.18.16.13:26379"
  password = ""
  db = 0

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
i can not reproduce the bug,most of time seaweedfs work very good,it only happend twice.

[qszxnp]

i found the issue https://github.com/chrislusf/seaweedfs/issues/1113， but i think it is different situation

[chrislusf]

added a fix. the exact line of code is a little different now.