Event observers fire from disabled modules

[scottsb]

Magento will still fire observers for disabled modules.

Besides simply triggering unwanted functionality, this can also potentially cause fatal errors if the module was disabled before the install scripts ever ran, as the observer will expect the module to be installed (and any schema/data changes to be applied), which it won't be in this case.

Preconditions

Magento 2.1.3

Steps to reproduce

1. Add the code for a module that has a setup script with schema changes used by an observer (e.g., Magento_AdminNotification), but do not yet run setup:upgrade.
2. Disable the module.
3. Run setup:upgrade. Because the module is disabled, schema changes will not be made (correctly so).
4. Perform action on site triggering observer that assumes database schema (e.g., log into admin when there is a pending notification).

Expected result

Observer is not fired, since module is disabled.

Actual result

Observer is fired, causing a potentially fatal error if it assumes schema changes have occurred.

[Stas94]

@scottsb Please add more details to your description of the steps you followed when identifying this issue. Screenshots or logs would be helpful, too.

[scottsb]

Is there a particular area you want clarification on? I already provided the steps to reproduce. (For what it's worth, the example I cite of Magento_AdminNotification isn't just hypothetical; it's the actual module we had disabled that caused us to run into this, so you could do the same.)

[ghost]

OK Op 5 jul. 2017 21:59 schreef "Scott Buchanan" <notifications@github.com>:

…

Is there a particular area you want clarification on? I already provided the steps to reproduce. (For what it's worth, the example I cite of Magento_AdminNotification isn't just hypothetical; it's the actual module we had disabled that caused us to run into this, so you could do the same.) — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#9948 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AS5o-mn9LwrpmiTgutrrjSqlTJ4yYWblks5sK-sqgaJpZM4N6Bts> .

[scottsb]

I did just clarify the problem statement in the issue. The fundamental bug is simply that event observers in disabled modules still run. My steps to reproduce illustrate how this can lead to a fatal error, though obviously there are many ways this could fail since code is running that's supposed to be disabled.

[magento-engcom-team]

@scottsb, thank you for your report.
We've created internal ticket(s) MAGETWO-71009 to track progress on the issue.

[thiagolima-bm]

I am working on it #SQUASHTOBERFEST

[shikhamis11]

I also tried to reproduce this issue on magento 2.3.4 instance but it is not reproducible now
@scottsb can you confirm the same ?