Reflector 10.0.6.546 -- incorrect C# code involving "Foo?.Bar()"

GlennSlayden

The .NET 4.7.2 overload  System.Xml.XmlReader.Create(Stream, XmlReaderSettings, String) in System.Xml.dll has the following IL:

.method public hidebysig static class XmlReader Create(class Stream input, class XmlReaderSettings settings, string baseUri) cil managed { .maxstack 8 L_0000: ldarg.1 L_0001: brtrue.s L_000a L_0003: newobj instance void XmlReaderSettings::.ctor() L_0008: starg.s settings L_000a: ldarg.1 L_000b: ldarg.0 L_000c: ldnull L_000d: ldarg.2 L_000e: ldnull L_000f: callvirt instance class XmlReader XmlReaderSettings::CreateReader(class Stream, class Uri, string, class XmlParserContext) L_0014: ret }

Reflector 10.0.6.546 renders the C# incorrectly:

public static XmlReader Create(Stream input, XmlReaderSettings settings, string baseUri) => settings?.CreateReader(input, null, baseUri, null); It is not correct because the above C# code will do nothing if 'null' is passed for 'settings', whereas the IL constructs a new instance upon which to invoke the 'CreateReader' function. A correct C# version would be: public static XmlReader Create(Stream input, XmlReaderSettings settings, string baseUri) => (settings ?? new XmlReaderSettings()).CreateReader(input, null, baseUri, null);

Technically, I suppose, if you want to mirror the IL exactly, it should be...

public static XmlReader Create(Stream input, XmlReaderSettings settings, string baseUri) => (settings ?? (settings = new XmlReaderSettings())).CreateReader(input, null, baseUri, null);

...wherein the new instance is stored in argument slot 1 'settings', but I don't see how this could matter here (since it's not a visible memory location).

Jessica R

Thanks for your post @GlennSlayden!

We don't have the ETA yet, but this will be fixed within the next release. I'll post here once that's available.

Jessica R

Hi there!

Just wanted to clarify that there was a release that we quickly put out earlier this week to resolve a security risk we learned of. The fix for this .NET 4.7.2 issue didn't make it into there, but it will still be in the next one.

GlennSlayden

Ok, thanks for keeping me posted.

Russell D

This is now fixed in v10.0.8.814, available on CfU here: https://download.red-gate.com/checkforupdates/ReflectorInstaller/ReflectorInstaller_10.0.8.814.exe.