[release/3.1] Check if parameter.Name is not null before comparing it with query pa…

[smitpatel]

…rameter

Resolves #20485

Parameters which are used inside lambda should get replaced with appropriate shaper/selector.
All other parameters should be query parameters otherwise it is an error.

[smitpatel]

Description

EF does special processing for certain parameters which are created by query during parameter extraction (for caching). To do this we compare the prefix of parameter name. This threw NRE when a parameter which had no name encountered.
Fix is to do null safe comparison. If parameter does not have name then we don't need to do any processing required for query parameter.

Customer Impact

Error for dynamically generated queries by multiple different libraries as parameter name is not required during expression tree generation.

How found

Reported by multiple customers.

Test coverage

Added a manually build expression with null parameter.Name which fails without this fix in the manner reported by customers.

Regression?

Yes.

Risk

Low. Fix only affects make comparison null safe without affecting existing functionality.

[ajcvickers]

@smitpatel Can you add a regression test that creates a couple of expression trees without parameter names?

Also, I think this likely is a regression in the sense that I think that we handled this case in the previous pipeline, or am I wrong about that?

[smitpatel]

Updated. Added regression test and quirk.

[ajcvickers]

@smitpatel Approved by tactics for 3.1.4. Please merge ASAP.