Fix a crash I introduced in r159212.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159279 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index a8aabb6..4de157e 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -1290,7 +1290,7 @@
   // Lookup doesn't work for destructors, so handle them separately.
   if (isa<CXXDestructorDecl>(this)) {
     CXXMethodDecl *MD = RD->getDestructor();
-    if (recursivelyOverrides(MD, this))
+    if (MD && recursivelyOverrides(MD, this))
       return MD;
     return NULL;
   }
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 4dd6f0b..bc77e6f 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -10859,6 +10859,8 @@
   if (!MostDerivedClassDecl)
     return;
   CXXMethodDecl *DM = MD->getCorrespondingMethodInClass(MostDerivedClassDecl);
+  if (!DM)
+    return;
   SemaRef.MarkAnyDeclReferenced(Loc, DM);
 } 
 
diff --git a/test/CodeGenCXX/devirtualize-virtual-function-calls.cpp b/test/CodeGenCXX/devirtualize-virtual-function-calls.cpp
index a0b6e8c..c5a4094 100644
--- a/test/CodeGenCXX/devirtualize-virtual-function-calls.cpp
+++ b/test/CodeGenCXX/devirtualize-virtual-function-calls.cpp
@@ -71,3 +71,15 @@
     b->foo::~foo();
   }
 }
+
+namespace test3 {
+  // Test that we don't crash in this case.
+  struct B {
+  };
+  struct D : public B {
+  };
+  void f(D d) {
+    // CHECK: define void @_ZN5test31fENS_1DE
+    d.B::~B();
+  }
+}