Bugzilla

**Affected versions**
* Updates on Firefox beta channel (For Fx 75.0b_x) 
* Updates on Firefox nightly channel ( For Fx 76.0a_x)

**Unaffected versions**
* Firefox 68.6.0esr (BuildId:20200305175243).
* Firefox 74.0 (disabled). 

**Affected platforms**
* macOS 10.14
* Windows 10 64bit
* Ubuntu 18.04 64bit.

**Steps to reproduce**

In order to easily reproduce this issue you can simulate a poor internet connection by using softwares like NetLimiter.

1. Launch an older version of Firefox (ex. 75.0b7).
2. Type “update firefox” inside the Address Bar.
3. Click the “Restart to Update” button while the update download process is still running.

**Expected result**
*  Firefox restarts and the latest version is installed.

**Actual result**
*  If the update download was not completed when the “Restart to Update” button was pressed Firefox simply restarts and the user doesn’t have the latest Firefox version.

**Notes**
* This may generate user confusion since the intervention card prompts the user that “The latest Firefox is downloaded and ready to install” but the update download process was not finished and Firefox simply restarts with the same (old) version after interacting with the "Restart to Update" button".

**Affected versions**
* Updates on Firefox beta channel (For Fx 75.0b_x) 
* Updates on Firefox nightly channel ( For Fx 76.0a_x)

**Unaffected versions**
* Firefox 68.6.0esr (BuildId:20200305175243).
* Firefox 74.0 (disabled). 

**Affected platforms**
* macOS 10.14
* Windows 10 64bit
* Ubuntu 18.04 64bit.

**Steps to reproduce**

In order to easily reproduce this issue you can simulate a poor internet connection by using softwares like NetLimiter.

1. Launch an older version of Firefox (ex. 75.0b7).
2. Type “update firefox” inside the Address Bar.
3. Click the “Restart to Update” button while the update download process is still running.

**Expected result**
*  Firefox restarts and the latest version is installed.

**Actual result**
*  If the update download was not completed when the “Restart to Update” button was pressed Firefox simply restarts and the user doesn’t have the latest Firefox version.

**Notes**
* This may generate user confusion since the intervention card prompts the user that “The latest Firefox is downloaded and ready to install” but the update download process was not finished and Firefox simply restarts with the same (old) version after interacting with the "Restart to Update" button.