Critical regression introduced in Mapster 7.3.0 when mapping to existing objects

[andrerav]

There are numerous issues that have been reported since the release of 7.3.0 that seem to have a common theme -- performing a map to an existing object has a tendency to create a new object instance instead of preserving the instance being mapped. So far it seems that the following issues have reported this:

• Mapping from one existing object to another and Mapster is returning generated and unwanted values #427
• Meaning of mapping to an existing object? #430
• _mapper.Map(src, dest) stopped working after upgrading to Mapster 7.3.0 #498
• Potential regression from minor versions 7.20 --> 7.30 #485
• Error adapt existing object with private property #482
• Invalid mapping to exists class if source is object #524

Other possibly related issues:

• How to properly map to existing collections? #546

I'm working on investigating which chance in 7.3.0 that might have introduced this issue. I will update this issue when I have new information to share.

[satano]

Hello.

In this case, should not be version 7.3.0 marked as deprecated because of critical bugs in nuget.org?

[doddgu]

hi, is there any progress?

[DocSvartz]

Hello, new instanse always created if TDestination does not have a public constructor without parameters. Maybe this has something to do with the problem.
In this case RecordTypeAdapter is selected for Class

Class is detected as Record in

Mapster/src/Mapster/Utils/ReflectionUtils.cs

Line 161 in 04ac871

public static bool IsRecordType(this Type type)

[andrerav]

Thanks to @DocSvartz this issue has been partially fixed. See #634 for details.

[DocSvartz]

Hello @andrerav , have you had problems with dictionaries ?
The generic KeyValuePair has always been detect as a record.
when updating you always received new instanse KeyValuePair and include member if then has been detect as record
new KeyValuePair<FakeRecordKey,FakeRecordValue> (New _Key, new _Value)

[DocSvartz]

@andrerav I open PR #646 When 2 Step of Fixing this problemm :)