Index: llvm/lib/Support/VirtualFileSystem.cpp
===================================================================
--- llvm/lib/Support/VirtualFileSystem.cpp
+++ llvm/lib/Support/VirtualFileSystem.cpp
@@ -753,6 +753,7 @@
         if (HardLinkTarget)
           Child.reset(new detail::InMemoryHardLink(P.str(), *HardLinkTarget));
         else {
+          assert(Buffer && "Non-HardLink without a buffer?");
           // Create a new file or directory.
           Status Stat(P.str(), getNextVirtualUniqueID(),
                       llvm::sys::toTimePoint(ModificationTime), ResolvedUser,
@@ -791,6 +792,7 @@
       if (I != E)
         return false;
 
+      assert(Buffer);
       // Return false only if the new file is different from the existing one.
       if (auto Link = dyn_cast<detail::InMemoryHardLink>(Node)) {
         return Link->getResolvedFile().getBuffer()->getBuffer() ==