Consider loosening byte[] rules in resx resources

[rainersigwald]

originally by @ericstj at dotnet/project-system#9526 (comment)

it's being treated as a Activator type resource.

Here's the relevant code in MSBuild:

msbuild/src/Tasks/ResourceHandling/MSBuildResXReader.cs

Lines 222 to 280 in 1a51dd8

	private static void AddLinkedResource(string resxFilename, bool pathsRelativeToBasePath, List<IResource> resources, string name, string value)
	{
	string[] fileRefInfo = ParseResxFileRefString(value);
	string fileName = FileUtilities.FixFilePath(fileRefInfo[0]);
	string fileRefType = fileRefInfo[1];
	if (pathsRelativeToBasePath)
	{
	fileName = Path.Combine(
	FileUtilities.GetDirectory(
	FileUtilities.NormalizePath(resxFilename)),
	fileName);
	}
	if (IsString(fileRefType))
	{
	string fileRefEncoding = null;
	if (fileRefInfo.Length == 3)
	{
	fileRefEncoding = fileRefInfo[2];
	#if RUNTIME_TYPE_NETCORE
	// Ensure that all Windows codepages are available.
	// Safe to call multiple times per https://docs.microsoft.com/en-us/dotnet/api/system.text.encoding.registerprovider
	Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
	#endif
	}
	// from https://github.com/dotnet/winforms/blob/a88c1a73fd7298b0a5c45251771f439262016826/src/System.Windows.Forms/src/System/Resources/ResXFileRef.cs#L231-L241
	Encoding textFileEncoding = fileRefEncoding != null
	? Encoding.GetEncoding(fileRefEncoding)
	: Encoding.Default;
	using (StreamReader sr = new StreamReader(fileName, textFileEncoding))
	{
	resources.Add(new StringResource(name, sr.ReadToEnd(), resxFilename));
	return;
	}
	}
	else if (IsByteArray(fileRefType))
	{
	byte[] byteArray = File.ReadAllBytes(fileName);
	resources.Add(new LiveObjectResource(name, byteArray));
	return;
	}
	else if (IsMemoryStream(fileRefType))
	{
	// See special-case handling in ResXFileRef
	// https://github.com/dotnet/winforms/blob/689cd9c69e632997bc85bf421af221d79b12ddd4/src/System.Windows.Forms/src/System/Resources/ResXFileRef.cs#L293-L297
	byte[] byteArray = File.ReadAllBytes(fileName);
	resources.Add(new LiveObjectResource(name, new MemoryStream(byteArray)));
	return;
	}
	resources.Add(new FileStreamResource(name, fileRefType, fileName, resxFilename));
	}

MSbuild is registering as activator resource: https://github.com/dotnet/msbuild/blob/1a51dd82a24e26b6aac68e29414182fa56fbb573/src/Tasks/ResourceHandling/MSBuildResXReader.cs#L279C31-L279C49

msbuild/src/Tasks/ResourceHandling/FileStreamResource.cs

Line 47 in 1a51dd8

preserializedResourceWriter.AddActivatorResource(Name, fileStream, TypeAssemblyQualifiedName, closeAfterWrite: true);

That's wrong, it should be treating as byte[], but MSBuild is only treating this as a byte array if it has both System.Byte[] and mscorlib

msbuild/src/Tasks/ResourceHandling/MSBuildResXReader.cs

Line 293 in 1a51dd8

return fileRefType.IndexOf("System.Byte[]") != -1 && fileRefType.IndexOf("mscorlib") != -1;

Here's what I see in the latest resx:

  <data name="ProgramSource" type="System.Resources.ResXFileRef, System.Windows.Forms">
    <value>Program.cs;System.Byte[]</value>
  </data>

Repro: conRes.zip

So I can workaround this by adding ,mscorlib to the resx.

  <data name="ProgramSource" type="System.Resources.ResXFileRef, System.Windows.Forms">
-    <value>Program.cs;System.Byte[]</value>
+    <value>Program.cs;System.Byte[],mscorlib</value>
  </data>

Maybe MSBuild could broaden that check to consider this specific case of no core assembly name. @rainersigwald

[rainersigwald]

@melytc it looks like you changed the resource editor to put ,mscorlib in there again; do you think we should change MSBuild as @ericstj suggested?

[melytc]

What @ericstj described, where we weren't saving the assembly information for the resource correctly, was a bug on our side. I don't think you need to change MSBuild, as our goal is to save the resource as we were doing before with the legacy resource editor. :)