taginclude & tagexclude ignore global_tags in 1.9

[tuukkamustonen]

Relevant telegraf.conf:

[global_tags]
  region = "eu-west-1"
  environment = "prod"
  component = "client_api"

[[inputs.mem]]
  fieldpass = ["free", "available"]
  taginclude = ["AutoScalingGroupName"]
  [inputs.mem.tags]
    AutoScalingGroupName = "foobar"

I am outputting to CloudWatch, but I think that's irrelevant here.

System info:

$ uname -a
Linux ip-xxx 4.9.0-8-amd64 #1 SMP Debian 4.9.130-2 (2018-10-27) x86_64 GNU/Linux
$ dpkg -l | grep -i telegraf
ii  telegraf                      1.9.1-1                        amd64        Plugin-driven server agent for reporting metrics into InfluxDB.

Steps to reproduce:

Run with given configuration.

Expected behavior:

taginclude is supposed to only leave AutoScalingGroupName in plugin's tags. This worked in previous versions (at least in 1.8.3) but no longer in 1.9 - all global tags are included despite above configuration.

Actual behavior:

All tags (AutoScalingGroupName, region, environment, component) are included in output.

Additional info:

Even tried excluding global tags with:

tagexclude = ["region", "environment", "component"]

...but that didn't have any effect, either.