Affected versions

• Nightly 95.0a1
• Beta 94.0b1
• Release 93.0

Affected platforms

• Ubuntu 16.04 x86

Steps to reproduce

1. Open the terminal.
2. Type "ping forcesafesearch.google.com" and press the "Enter" key. ( If the returning address does not look like "216.239.38.120" use command ping -4 forcesafesearch.google.com )
3. Open Notepad with Administrator privileges and edit the hosts file.
   ("sudo nano /private/etc/hosts" for macOS and "sudo nano /etc/hosts" Linux)
4. Create an entry at the end of the file using the IP from step 2. eg. <IP from step 2> www.google.com #forcesafesearch.
5. Save the hosts file.
6. Open Firefox.
7. Navigate to about:config and check the value of the network.trr.mode pref.

• value is set to 0.

8. Navigate to about:config and add the "doh-rollout.enabled" boolean pref with the "true" value.

• The DoH notification doorhanger is not displayed.

9. Navigate to about:config and check the value of the network.trr.mode pref.

• The value of the preference is 0.

10. Navigate to about:telemetry#events-tab

Expected result

• The following ping is displayed:
  {"evaluateReason": "startup", "steeredProvider": "", "captiveState": "not_captive", "networkID": "+gDUtRu5owUwhy3k3X2bzAs3v/aDgoRgyfqWyeNcbmg=", "canaries": "", "filtering": "google", "enterprise": ""}

Actual result

• The following ping is displayed:
  {"evaluateReason": "startup", "steeredProvider": "", "captiveState": "not_captive", "networkID": "nCF2UA6tk2uquetCB624/sx4ukA/vVpGEIgZETc8rwo=", "canaries": "", "filtering": "", "enterprise": "", "platform": ""}
• "google" is missing from the displayed event ping.

Regression range

• This doesn't seem to be a regression, at least not a recent one, since I'm seeing the same behavior on Release 93.0. I'll investigate more, in case of an old regression.

Additional notes

• I was only able to reproduce this on Ubuntu 16.04 x86 so far. I can investigate more, if needed.

I was not able to reproduce the issue on following OSs (Win10x64, Ubuntu 20.4, Mac 10.13) using NB 95.0a1 (20211005094529 and 20211031213949). Could be specific for Ubuntu 16.04!

Win10 ({"evaluateReason": "startup", "steeredProvider": "", "captiveState": "not_captive", "networkID": "0HZAa/4Dx9zpiZ9MfezFUj1TS7c92LBex7mYka66/dk=", "canaries": "", "filtering": "google", "enterprise": "", "platform": ""} )

If it only happens on Ubuntu 16.04 this is potentially a bug on that platform. Not a high priority.

I've investigated this issue in order to find out if it was a regression; I was able to reproduce the bug all the way back to Firefox 80.0 with Ubuntu 18.04 x86. Older builds than this do not trigger the ping in about:telemetry#events-tab page.