PR29166: when merging declarations with typedef names for linkage purposes,

don't assume that the anonymous struct will be part of the most recent
declaration of the typedef.

llvm-svn: 280136

clang/lib/Serialization/ASTReaderDecl.cpp

@@ -2887,7 +2887,7 @@ static NamedDecl *getDeclForMerging(NamedDecl *Found,
     return nullptr;
 
   if (auto *TND = dyn_cast<TypedefNameDecl>(Found))
-    return TND->getAnonDeclWithTypedefName();
+    return TND->getAnonDeclWithTypedefName(/*AnyRedecl*/true);
 
   return nullptr;
 }

clang/test/Modules/merge-name-for-linkage.cpp

@@ -2,6 +2,7 @@
 // RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -I%S/Inputs/merge-name-for-linkage -verify %s
 // expected-no-diagnostics
 typedef union {} pthread_mutex_t;
+typedef pthread_mutex_t pthread_mutex_t;
 #include "a.h"
 pthread_mutex_t x;
 #include "b.h"