Unable to use generic types in TryConvertTo method

[PeterKvayt]

Which Umbraco version are you using? (Please write the exact version, example: 10.1.0)

15.1.1

Bug summary

I have a document type with property which is typed of List. I have notification handler on saved content event. Notification handler has IContent. I have the following code:

IContent myContent // it is my content
var typedValue = myContent.GetValue<List<Guid>>("myPropertyAlias");

In the code above I trying to get typed value.
If we look at the implementation of the GetValue<T> method we find out that it uses TryConvertTo which is uses GetCachedGenericNullableType. Here we have the following check:

if (type.GetGenericTypeDefinition() == typeof(Nullable<>))

So if we call myContent.GetValue<List<Guid>> check will return false.
GetCachedGenericNullableType called here and here and for type List<Guid> method GetCachedGenericNullableType will return null.
According to this comment the following check should consume non nullable types (like my List<Guid>), but we have condition != null.
I think it is a mistake to have two the same checks (!= null) here and here.

Specifics

No response

Steps to reproduce

Try to get any typed generic value from IContent using GetValue<T> like GetValue<IEnumerable<string>>

Expected result / actual result

Actual result: for generic types value is null
Expected result: for generic types value is not null

[github-actions]

Hi there @PeterKvayt!

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[NguyenThuyLan]

Hi @PeterKvayt , could you please let me know which property editor you want to get value and convert into List Guid? 🤔