diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 0263967..070f784 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -5441,18 +5441,18 @@
         }
     }
   }
-  for (ArrayRef<const Expr*>::iterator I = Args.begin(), E = Args.end();
-       I != E; ++I) {
-    if (!Evaluate(ArgValues[I - Args.begin()], Info, *I)) {
+  for (unsigned Idx = 0; Idx < Args.size(); Idx++) {
+    if (!Evaluate(ArgValues[Idx], Info, Args[Idx])) {
       // If we're checking for a potential constant expression, evaluate all
       // initializers even if some of them fail.
       if (!Info.noteFailure())
         return false;
       Success = false;
     } else if (!ForbiddenNullArgs.empty() &&
-               ForbiddenNullArgs[I - Args.begin()] &&
-               ArgValues[I - Args.begin()].isNullPointer()) {
-      Info.CCEDiag(*I, diag::note_non_null_attribute_failed);
+               ForbiddenNullArgs[Idx] &&
+               ArgValues[Idx].isLValue() &&
+               ArgValues[Idx].isNullPointer()) {
+      Info.CCEDiag(Args[Idx], diag::note_non_null_attribute_failed);
       if (!Info.noteFailure())
         return false;
       Success = false;
diff --git a/test/SemaCXX/attr-nonnull.cpp b/test/SemaCXX/attr-nonnull.cpp
index 764e8d8..21eedcf 100644
--- a/test/SemaCXX/attr-nonnull.cpp
+++ b/test/SemaCXX/attr-nonnull.cpp
@@ -77,10 +77,11 @@
 constexpr int i32 = f3(0, &c);
 
 __attribute__((nonnull(4))) __attribute__((nonnull)) //expected-error {{out of bounds}}
-constexpr int f4(const int*, const int*) {
+constexpr int f4(const int*, const int*, int) {
   return 0;
 }
-constexpr int i4 = f4(&c, 0); //expected-error {{constant expression}} expected-note {{null passed}}
-constexpr int i42 = f4(0, &c); //expected-error {{constant expression}} expected-note {{null passed}}
+constexpr int i4 = f4(&c, 0, 0); //expected-error {{constant expression}} expected-note {{null passed}}
+constexpr int i42 = f4(0, &c, 1); //expected-error {{constant expression}} expected-note {{null passed}}
+constexpr int i43 = f4(&c, &c, 0);
 
 }
\ No newline at end of file