System.ComponentModel.PropertyDescriptorCollection logic should be consistent about null PropertyDescriptor

[krwq]

Found during adding nullable annotations to TypeConverter (#54961)

Current logic of PropertyDescriptorCollection is inconsistent about allowing null PropertyDescriptor, i.e.:

• constructors taking PropertyDescriptor[] do not guard against null values
• Add, Insert, Remove doesn't have a null check
• Find if it encounters null property when searching will in many cases throw NRE as it accesses Name without any null checks
• anything triggering sorting (InternalSort) for non empty collection will most likely throw NRE because it accesses Name without null checks

I've conservatively marked them as non-accepting the null as that will provide most intuitive experience. The solution here is to do one of the following:

• add null checks and throw on null
• allow for nulls everywhere

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Issue Details

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Found during adding nullable annotations to TypeConverter (#54961)

Current logic of PropertyDescriptorCollection is inconsistent about allowing null PropertyDescriptor, i.e.:

• constructors taking PropertyDescriptor[] do not guard against null values
• Add, Insert, Remove doesn't have a null check
• Find if it encounters null property when searching will in many cases throw NRE as it accesses Name without any null checks
• anything triggering sorting (InternalSort) for non empty collection will most likely throw NRE because it accesses Name without null checks

I've conservatively marked them as non-accepting the null as that will provide most intuitive experience. The solution here is to do one of the following:

• add null checks and throw on null
• allow for nulls everywhere

Author:	krwq
Assignees:	-
Labels:	area-System.ComponentModel
Milestone:	-