Breaking change for IdentityRole object not documented

[GorazdDim]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

The IdentityRole.ConcurrencyStamp property has a changed type and default value from the 6.0.33 version to the 7.0.0 version.

In the 6.0.33 version the property is defined like: public virtual string ConcurrencyStamp { get; set; } = Guid.NewGuid().ToString();

In the 7.0.0 version the property is defined like: public virtual string? ConcurrencyStamp { get; set; }

This is a breaking change and it is not documented anywhere. After a short debugging session I found the issue, but I felt i needed to report this.

Expected Behavior

No response

Steps To Reproduce

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Exceptions (if any)

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.NET Version

No response

Anything else?

No response

[MackinnonBuck]

It looks like this change was made accidentally. We should consider adding a default value back.

Out of curiosity, how did this break your app?

[GorazdDim]

I implemented custom logic to compare the ConcurrencyStamp to handle concurrency errors manually, instead of relying on catching a DbUpdateConcurrencyException. Previously, the code expected a new Role to have an initial value for the ConcurrencyStamp. However, now that the initial value is null, the comparison logic incorrectly treats this as a concurrency error.

If I remove my custom logic the IdentityFramework properly handles the concurrency, which is probably why this issue wasn't noticed.