Parsing assembly qualified type name fails

[rolfbjarne]

Description

Parsing the type name "System.Int32, , System.Private.CoreLib.dll" fails in the latest .NET 8 builds.

Reproduction Steps

Test code:

var t = Type.GetType ("System.Int32, , System.Private.CoreLib.dll");
Console.WriteLine (t);

Expected behavior

This should be printed:

System.Int32, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e

Actual behavior

An exception:

Unhandled exception. System.IO.FileLoadException: The given assembly name was invalid.
File name: ', System.Private.CoreLib.dll'
   at System.Reflection.AssemblyNameParser.ThrowInvalidAssemblyName()
   at System.Reflection.AssemblyNameParser.Parse()
   at System.Reflection.AssemblyNameParser.Parse(String name)
   at System.Reflection.AssemblyName..ctor(String assemblyName)
   at System.Reflection.TypeNameParser.ResolveAssembly(String assemblyName)
   at System.Reflection.TypeNameParser.GetType(String typeName, ReadOnlySpan`1 nestedTypeNames, String assemblyNameIfAny)
   at System.Reflection.TypeNameParser.NamespaceTypeName.ResolveType(TypeNameParser& parser, String containingAssemblyIfAny)
   at System.Reflection.TypeNameParser.GetType(String typeName, Func`2 assemblyResolver, Func`4 typeResolver, Assembly requestingAssembly, Boolean throwOnError, Boolean ignoreCase, Boolean extensibleParser)
   at System.Type.GetType(String typeName)

Regression?

Yes, the code works fine in .NET 7.

Known Workarounds

No response

Configuration

/Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/dotnet --info
.NET SDK:
 Version:   8.0.100-preview.4.23178.2
 Commit:    69e28735b9

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  13.3
 OS Platform: Darwin
 RID:         osx.13-x64
 Base Path:   /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk/8.0.100-preview.4.23178.2/

.NET workloads installed:
 [macos]
   Installation Source: SDK 8.0.100-preview.4
   Manifest Version:    13.1.8527-ci.darc-net8-0-78d17446-9936-45f9-8740-af082689e6f6/8.0.100-preview.2
   Manifest Path:       /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk-manifests/8.0.100-preview.2/microsoft.net.sdk.macos/WorkloadManifest.json
   Install Type:        FileBased
 [ios]
   Installation Source: SDK 8.0.100-preview.4
   Manifest Version:    16.2.8527-ci.darc-net8-0-78d17446-9936-45f9-8740-af082689e6f6/8.0.100-preview.2
   Manifest Path:       /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk-manifests/8.0.100-preview.2/microsoft.net.sdk.ios/WorkloadManifest.json
   Install Type:        FileBased
 [maccatalyst]
   Installation Source: SDK 8.0.100-preview.4
   Manifest Version:    16.2.8527-ci.darc-net8-0-78d17446-9936-45f9-8740-af082689e6f6/8.0.100-preview.2
   Manifest Path:       /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk-manifests/8.0.100-preview.2/microsoft.net.sdk.maccatalyst/WorkloadManifest.json
   Install Type:        FileBased
 [tvos]
   Installation Source: SDK 8.0.100-preview.4
   Manifest Version:    16.1.9315-ci.darc-net8-0-78d17446-9936-45f9-8740-af082689e6f6/8.0.100-preview.2
   Manifest Path:       /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk-manifests/8.0.100-preview.2/microsoft.net.sdk.tvos/WorkloadManifest.json
   Install Type:        FileBased

Host:
  Version:      8.0.0-preview.4.23176.4
  Architecture: x64
  Commit:       8d5f520838

.NET SDKs installed:
  8.0.100-preview.4.23178.2 [/Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 8.0.0-preview.4.23176.6 [/Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 8.0.0-preview.4.23176.4 [/Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/shared/Microsoft.NETCore.App]

Other architectures found:
  None

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

Other information

It happened somewhere in this range: edb161a...8d5f520

I'm guessing this is the culprit: #83484

CC @jkotas

Tagging subscribers to this area: @dotnet/area-system-reflection
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

Parsing the type name "System.Int32, , System.Private.CoreLib.dll" fails in the latest .NET 8 builds.

Reproduction Steps

Test code:

var t = Type.GetType ("System.Int32, , System.Private.CoreLib.dll");
Console.WriteLine (t);

Expected behavior

This should be printed:

System.Int32, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e

Actual behavior

An exception:

Unhandled exception. System.IO.FileLoadException: The given assembly name was invalid.
File name: ', System.Private.CoreLib.dll'
   at System.Reflection.AssemblyNameParser.ThrowInvalidAssemblyName()
   at System.Reflection.AssemblyNameParser.Parse()
   at System.Reflection.AssemblyNameParser.Parse(String name)
   at System.Reflection.AssemblyName..ctor(String assemblyName)
   at System.Reflection.TypeNameParser.ResolveAssembly(String assemblyName)
   at System.Reflection.TypeNameParser.GetType(String typeName, ReadOnlySpan`1 nestedTypeNames, String assemblyNameIfAny)
   at System.Reflection.TypeNameParser.NamespaceTypeName.ResolveType(TypeNameParser& parser, String containingAssemblyIfAny)
   at System.Reflection.TypeNameParser.GetType(String typeName, Func`2 assemblyResolver, Func`4 typeResolver, Assembly requestingAssembly, Boolean throwOnError, Boolean ignoreCase, Boolean extensibleParser)
   at System.Type.GetType(String typeName)

Regression?

Yes, the code works fine in .NET 7.

Known Workarounds

No response

Configuration

/Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/dotnet --info
.NET SDK:
 Version:   8.0.100-preview.4.23178.2
 Commit:    69e28735b9

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  13.3
 OS Platform: Darwin
 RID:         osx.13-x64
 Base Path:   /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk/8.0.100-preview.4.23178.2/

.NET workloads installed:
 [macos]
   Installation Source: SDK 8.0.100-preview.4
   Manifest Version:    13.1.8527-ci.darc-net8-0-78d17446-9936-45f9-8740-af082689e6f6/8.0.100-preview.2
   Manifest Path:       /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk-manifests/8.0.100-preview.2/microsoft.net.sdk.macos/WorkloadManifest.json
   Install Type:        FileBased
 [ios]
   Installation Source: SDK 8.0.100-preview.4
   Manifest Version:    16.2.8527-ci.darc-net8-0-78d17446-9936-45f9-8740-af082689e6f6/8.0.100-preview.2
   Manifest Path:       /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk-manifests/8.0.100-preview.2/microsoft.net.sdk.ios/WorkloadManifest.json
   Install Type:        FileBased
 [maccatalyst]
   Installation Source: SDK 8.0.100-preview.4
   Manifest Version:    16.2.8527-ci.darc-net8-0-78d17446-9936-45f9-8740-af082689e6f6/8.0.100-preview.2
   Manifest Path:       /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk-manifests/8.0.100-preview.2/microsoft.net.sdk.maccatalyst/WorkloadManifest.json
   Install Type:        FileBased
 [tvos]
   Installation Source: SDK 8.0.100-preview.4
   Manifest Version:    16.1.9315-ci.darc-net8-0-78d17446-9936-45f9-8740-af082689e6f6/8.0.100-preview.2
   Manifest Path:       /Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk-manifests/8.0.100-preview.2/microsoft.net.sdk.tvos/WorkloadManifest.json
   Install Type:        FileBased

Host:
  Version:      8.0.0-preview.4.23176.4
  Architecture: x64
  Commit:       8d5f520838

.NET SDKs installed:
  8.0.100-preview.4.23178.2 [/Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 8.0.0-preview.4.23176.6 [/Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 8.0.0-preview.4.23176.4 [/Users/rolf/work/maccore/net8.0/xamarin-macios/builds/downloads/dotnet-sdk-8.0.100-preview.4.23178.2/shared/Microsoft.NETCore.App]

Other architectures found:
  None

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

Other information

It happened somewhere in this range: edb161a...8d5f520

I'm guessing this is the culprit: #83484

CC @jkotas

Author:	rolfbjarne
Assignees:	-
Labels:	area-System.Reflection, untriaged, needs-area-label
Milestone:	-

[stephentoub]

It happened somewhere in this range: edb161a...8d5f520

We're sure? Based purely on history I would have guessed I might have broken it a few months ago in https://github.com/dotnet/runtime/pull/79048/files#diff-6552989a804d7e6b6e1f065a88d8c17221ea6c6ad561d66348d2f85668f6261f.

[rolfbjarne]

It happened somewhere in this range: edb161a...8d5f520

We're sure? Based purely on history I would have guessed I might have broken it a few months ago in #79048 (files).

It started breaking in this maestro bump: dotnet/macios#17888

[jkotas]

I'm guessing this is the culprit: #83484

Yes, the behavior regressed with this change. I am working on a fix.

The expected behavior is not correct. System.Int32, , System.Private.CoreLib.dll is invalid type name - the extra comma makes it invalid. Type.GetType with throwOnError:false should return null for it. It is what it did in .NET 7.