Code generated by VB's On Error Resume Next causes "unassigned variable" compile errors

[siegfriedpammer]

This piece of code is from VB's My-namespace implementation of a Windows Forms project. (for the binary sample see #2033)

[DebuggerHidden]
private static T Create__Instance__<T>(T Instance) where T : Form, new()
{
	if (Instance?.IsDisposed ?? true)
	{
		if (m_FormBeingCreated != null)
		{
			if (m_FormBeingCreated.ContainsKey(typeof(T)))
			{
				throw new InvalidOperationException(Utils.GetResourceString("WinForms_RecursiveFormCreate"));
			}
		}
		else
		{
			m_FormBeingCreated = new Hashtable();
		}
		m_FormBeingCreated.Add(typeof(T), null);
		TargetInvocationException ex2; // <------- ex2 is probably missing the init flag
		try
		{
			return new T();
		}
		catch (TargetInvocationException ex) when (((Func<bool>)delegate
		{
			// Could not convert BlockContainer to single expression
			ProjectData.SetProjectError(ex);
			ex2 = ex;
			return ex2.InnerException != null;
		}).Invoke())
		{
			string resourceString = Utils.GetResourceString("WinForms_SeeInnerException", ex2.InnerException.Message);
			throw new InvalidOperationException(resourceString, ex2.InnerException);
		}
		finally
		{
			m_FormBeingCreated.Remove(typeof(T));
		}
	}
	return Instance;
}

[dgrunwald]

This doesn't look like On Error Resume Next.
Maybe this is just a regular VB exception filter?

The issue is that "// Could not convert BlockContainer to single expression" -- the ex2 = ex; assignment definitely happens in the exception filter, but due to our immediately-invoked-lambda hack, the C# compiler isn't clever enough to notice that ex2 is initialized.
Maybe ExpressionBuilder.VisitBlockContainer() needs to re-enable the init flag for any variables assigned within the block?