Unnecessary changelog records for tag add/change/remove

Environment

• Python version: 3.6.9
• NetBox version: 2.10.3

Steps to Reproduce

1. create two tags TagA and TagB
2. create a virtual-machine (or device)
3. add TagA to the virtual-machine
4. remove TagA and add TagB to the virtual-machine (in one request)
5. remove TagB from the virtual-machine

Expected Behavior

Steps 3., 4. and 5. create only one changelog record

Observed Behavior

Step 3. creates two changelog records (with the same request id), where only one record shows the tag add and one shows no change.

Step 4. creates three changelog records (with the same request id), where one record shows the TagA remove, one the TagB add, and one shows no change.

Step 5. creates two changelog records (with the same request id), where only one record shows the tag remove and one shows no change.

Here are the database extras_objectchange records for the above steps 2.-5.: https://gist.github.com/cloos/e7dd4c3b1f064098e4250e7cddb29c85

[jeremystretch]

This will be fixed in the upcoming v2.11 release.

[jeremystretch]

With the improvements made to change logging in v2.11 (see #5913), we should be able to update the first ObjectChange instance on m2m_changed instead of creating a second instance. I’m going to dig into this a bit more.