panic: close of closed channel

[DigitallyBorn]

Bug report

System info: [Include InfluxDB version, operating system name, and other relevant details]
version 1.4.2, branch 1.4, commit 6d2685d

Steps to reproduce:
Not sure. The database server has been stable for weeks.

Expected behavior: Server doesn't panic and crash.

Actual behavior: Server panic'ed and crashed.

Additional info:

panic: close of closed channel
goroutine 28674303 [running]:
github.com/influxdata/influxdb/query.(*QueryTask).kill(0xc43b0a3180, 0xc420216630, 0x240a8)
/go/src/github.com/influxdata/influxdb/query/query_executor.go:523 +0x8e
github.com/influxdata/influxdb/query.(*TaskManager).KillQuery(0xc420209620, 0x240a8, 0x10d14a0, 0xc42003b010)
/go/src/github.com/influxdata/influxdb/query/task_manager.go:206 +0x90
github.com/influxdata/influxdb/query.(*TaskManager).waitForQuery(0xc420209620, 0x240a8, 0xc422182060, 0xc4bdad9680, 0xc422182120)
/go/src/github.com/influxdata/influxdb/query/task_manager.go:274 +0x1a7
created by github.com/influxdata/influxdb/query.(*TaskManager).AttachQuery
/go/src/github.com/influxdata/influxdb/query/task_manager.go:176 +0x335

Immediately preceding those log entries were these (I'm not sure if they're relevant, since they appear to be successful events):

[I] 2017-12-10T02:45:50Z executing continuous query runner_cpu_daily (2017-12-10 02:45:40 +0000 UTC to 2017-12-10 02:45:50 +0000 UTC) service=continuous_querier
[I] 2017-12-10T02:45:50Z finished continuous query runner_cpu_daily, 1 points(s) written (2017-12-10 02:45:40 +0000 UTC to 2017-12-10 02:45:50 +0000 UTC) in 4.59884ms service=continuous_querier
[I] 2017-12-10T02:45:50Z finished continuous query runner_cpu_daily, 1 points(s) written (2017-12-10 02:45:40 +0000 UTC to 2017-12-10 02:45:50 +0000 UTC) in 4.59884ms service=continuous_querier

Otherwise there is normal incoming traffic from our own clients and telegraf.

[leafonsword]

Will 1.4.3 fix this bug？ I use 1.4.2 and ran into this bug~