1 files changed, 14 insertions, 0 deletions
diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index 4fb6051d6f58..847638b7bbeb 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -1622,10 +1622,18 @@ Decl *ASTNodeImporter::VisitRecordDecl(RecordDecl *D) {
 
   // We may already have a record of the same name; try to find and match it.
   RecordDecl *AdoptDecl = nullptr;
+  RecordDecl *PrevDecl = nullptr;
   if (!DC->isFunctionOrMethod()) {
     SmallVector<NamedDecl *, 4> ConflictingDecls;
     SmallVector<NamedDecl *, 2> FoundDecls;
     DC->getRedeclContext()->localUncachedLookup(SearchName, FoundDecls);
+
+    if (!FoundDecls.empty()) {
+      // We're going to have to compare D against potentially conflicting Decls, so complete it.
+      if (D->hasExternalLexicalStorage() && !D->isCompleteDefinition())
+        D->getASTContext().getExternalSource()->CompleteType(D);
+    }
+
     for (unsigned I = 0, N = FoundDecls.size(); I != N; ++I) {
       if (!FoundDecls[I]->isInIdentifierNamespace(IDNS))
         continue;
@@ -1652,6 +1660,8 @@ Decl *ASTNodeImporter::VisitRecordDecl(RecordDecl *D) {
           }
         }
 
+        PrevDecl = FoundRecord;
+
         if (RecordDecl *FoundDef = FoundRecord->getDefinition()) {
           if ((SearchName && !D->isCompleteDefinition())
               || (D->isCompleteDefinition() &&
@@ -1744,6 +1754,10 @@ Decl *ASTNodeImporter::VisitRecordDecl(RecordDecl *D) {
     LexicalDC->addDeclInternal(D2);
     if (D->isAnonymousStructOrUnion())
       D2->setAnonymousStructOrUnion(true);
+    if (PrevDecl) {
+      // FIXME: do this for all Redeclarables, not just RecordDecls.
+      D2->setPreviousDecl(PrevDecl);
+    }
   }
   
   Importer.Imported(D, D2);