Small fixes around repro loading/autodiff (#2585)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Work around for some issue seen with a repro.

* Small improvement in doing IDifferentable check.

2 files changed, 17 insertions, 3 deletions

diff --git a/source/slang/slang-ir-autodiff.cpp b/source/slang/slang-ir-autodiff.cpp
index 53e2ed0be..94417ea00 100644
--- a/source/slang/slang-ir-autodiff.cpp
+++ b/source/slang/slang-ir-autodiff.cpp
@@ -309,10 +309,15 @@ IRInst* AutoDiffSharedContext::findDifferentiableInterface()
             // TODO: This seems like a particularly dangerous way to look for an interface.
             // See if we can lower IDifferentiable to a separate IR inst.
             //
-            if (globalInst->getOp() == kIROp_InterfaceType &&
-                as<IRInterfaceType>(globalInst)->findDecoration<IRNameHintDecoration>()->getName() == "IDifferentiable")
+            if (auto intf = as<IRInterfaceType>(globalInst))
             {
-                return globalInst;
+                if (auto decor = intf->findDecoration<IRNameHintDecoration>())
+                {
+                    if (decor->getName() == toSlice("IDifferentiable"))
+                    {
+                        return globalInst;
+                    }
+                }
             }
         }
     }
diff --git a/source/slang/slang-repro.cpp b/source/slang/slang-repro.cpp
index f0df86129..fa997ba25 100644
--- a/source/slang/slang-repro.cpp
+++ b/source/slang/slang-repro.cpp
@@ -1065,6 +1065,15 @@ struct LoadContext
             for (const auto& pair : context.m_fileToPathInfoMap)
             {
                 CacheFileSystem::PathInfo* pathInfo = pair.Value;
+
+                // TODO(JS): It's not 100% clear why we are ending up 
+                // with entries that don't have a unique identity.
+                // For now we ignore adding to the unique map, because 
+                // if we do we'll have multiple entries with the same key
+                if (pathInfo->m_uniqueIdentity.getLength() == 0)
+                {
+                    continue;
+                }
                 SLANG_ASSERT(pathInfo->m_uniqueIdentity.getLength());
                 dstUniqueMap.Add(pathInfo->m_uniqueIdentity, pathInfo);
             }