Is changing protected to protected internal a binary-breaking change for users outside the assembly?

[RenderMichael]

Hello,

I am maintaining a library and I want to change a method from protected to protected internal for use within my code. According to the docs, this is a source-compatible change.

However, I wanted to make sure it did not break binary compatibility.

[333fred]

I do not expect that it is either a source or binary compatible change: https://sharplab.io/#v2:C4LglgNgPgAgTARgLACgYGYAE9MGFMDeqmJmADgE4D2wApgMZ0AmmYAdnRWwIYSYBuYCsACuvbABZMAWQAUASkLFSAX1RqUqDNjiYAIphB4lKUuWp1GtFlX60KFME1qSZCk2Y0qgA===. If the method is non-virtual, then it's probably fine, but if it can be overridden, then this is a breaking change in all aspects.

[RenderMichael]

My concern is with a virtual member, yes.

According to the docs, if you override a protected internal member in another assembly, you still only need protected override in the signature.

I was wondering if that meant such a change is binary compatible as well. Looking at the IL, protected turns into family and protected internal turns into famorassem. This means it's a binary break, right?

[333fred]

Alright, I wrote a quick test program, and it appears I am incorrect, and the guidance is correct. It is not a source or binary break.