From dc36fce3005d80eed07550e1a32f682e3e5e9990 Mon Sep 17 00:00:00 2001
From: Eric StJohn <ericstj@microsoft.com>
Date: Wed, 28 Jul 2021 17:45:49 -0700
Subject: [PATCH] Validate ref project references (#56488)

* Validate that reference assembly projects only reference other reference assembly projects

* Permit ref->src reference if src project produces reference assembly

* Move target to references.targets
---
 eng/references.targets | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/eng/references.targets b/eng/references.targets
index 6adcba9..7cfb604 100644
--- a/eng/references.targets
+++ b/eng/references.targets
@@ -49,4 +49,14 @@
     </ItemGroup>
   </Target>
 
+  <ItemDefinitionGroup>
+    <TargetPathWithTargetPlatformMoniker>
+      <IsReferenceAssembly>$(IsReferenceAssembly)</IsReferenceAssembly>
+    </TargetPathWithTargetPlatformMoniker>
+  </ItemDefinitionGroup>
+
+  <Target Name="ValidateReferenceAssemblyProjectReferences" Condition="'$(IsReferenceAssembly)' == 'true'" AfterTargets="ResolveReferences">
+    <Error Condition="'%(ReferencePath.ReferenceSourceTarget)' == 'ProjectReference' AND '%(ReferencePath.IsReferenceAssembly)' != 'true' AND '%(ReferencePath.ReferenceAssembly)' == ''"
+           Text="Reference assemblies must only reference other reference assemblies and '%(ReferencePath.ProjectReferenceOriginalItemSpec)' is not a reference assembly project and does not set 'ProduceReferenceAssembly'." />
+  </Target>
 </Project>
-- 
2.7.4