Huge Breaking Issue in Net7 with MemberInfo equality

[jogibear9988]

Description

If you compare 2 Memberinfos in Net7 from a Class and a Base they are equal in 7 but not in Previous Versions.
Cause of this my Database Mapping Framework did not work any more.
see issue: linq2db/linq2db#3823

Reproduction Steps

Try this code in Net6 it returns false, in 7 it returns true

    var i1 = typeof(a).GetProperty("c");
    var i2 = typeof(b).GetProperty("c");

    Console.WriteLine(i1 == i2);
    Console.ReadLine();

    class a
    {
        public string c { get; set; }
    }

    class b : a
    { }

Expected behavior

Code should return false

Actual behavior

returns tre

Regression?

Yes

Known Workarounds

None

Configuration

No response

Other information

No response

[jogibear9988]

And if you do:

   Console.WriteLine(i1.ReflectedType == i2.ReflectedType);

this will return false... So memberinfos with different properties are handled as equal

[jogibear9988]

Maybe a ReflectedType comparison is missing here: https://github.com/dotnet/runtime/blob/main/src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimePropertyInfo.cs#L59

[stephentoub]

cc: @buyaa-n, @jkotas

[jogibear9988]

With Fields it's also an issue. With Methods it works.

    var i1 = typeof(a).GetProperty("c");
    var i2 = typeof(b).GetProperty("c");
    Console.WriteLine(i1 == i2);
    Console.WriteLine(i1.ReflectedType == i2.ReflectedType);

    var i3 = typeof(a).GetMethod("aa");
    var i4 = typeof(b).GetMethod("aa");
    Console.WriteLine(i3 == i4);

    var i5 = typeof(a).GetField("d");
    var i6 = typeof(b).GetField("d");
    Console.WriteLine(i5 == i6);
    Console.WriteLine(i5.ReflectedType == i6.ReflectedType);

    Console.ReadLine();

    class a
    {
        public string c { get; set; }
        public void aa() { }
        public string d;
    }

    class b : a
    { }

[jogibear9988]

Could be a huge problem with linq2db and fluent mapping. It depends on the correct behavior.

[jogibear9988]

And a question, will there be an Hotfix?

[jkotas]

Note that this reproduces only under debugger with hot-reload enabled. You can work around this by disabling hot-reload.

Maybe a ReflectedType comparison is missing here: https://github.com/dotnet/runtime/blob/main/src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimePropertyInfo.cs#L59

ReflectedType comparison is missing in the Equals method. The CacheEquals method is fine.

[marek-safar]

/cc @lambdageek

[jogibear9988]

I've the issue also in VS when I disable Hotreload

[jogibear9988]

And also in release Mode.

[jogibear9988]

It don't appear to happen if you don't start from Visual Studio

[jogibear9988]

Now I understand why I don't saw this issue in my logfiles. I was looking why our App does not work in Net7 and thought this is the issue. But so it's not. It's only an issue while debugging. Now I need to look what's wrong without debugger...

[jogibear9988]

really? milestone 8.0.0?

[steveharter]

really? milestone 8.0.0?

We always start with current (8.0 here) then backport.

[jogibear9988]

Can someone tell me, how I could disable hot reload? So I could still debug.

the upper two switches don't seem to help, I still got the error.

[buyaa-n]

We always start with current (8.0 here) then backport.

Tag @ericstj @jeffhandley for porting the fix to 7.0

[ericstj]

Seems reasonable to backport. Regression from last release in a common scenario with non-trivial workaround. Proceed with fix in main then open the backport pr and add template when ready.

[jogibear9988]

@jkotas

Note that this reproduces only under debugger with hot-reload enabled. You can work around this by disabling hot-reload.

can you tell me how to disable it when I start the app from within visual studio?

[jkotas]

I just checked - it is not possible to completely disable hot-reload when running under debugger. Parts of it are automatically enabled when debugger is attached. I am sorry that the workaround that I have suggested does not work.

[jogibear9988]

@jkotas
maybe it should also be thought of? a way to disable hot reload?

[jkotas]

Yes, I agree: #78540