[clang-tidy] Fix a forwarding-reference-overload crash after the

ElaboratedType change.

After 15f3cd6bfc670ba6106184a903eb04be059e5977, the nss of
ElaboratedType can be null.

2 files changed, 16 insertions, 4 deletions

diff --git a/clang-tools-extra/clang-tidy/bugprone/ForwardingReferenceOverloadCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/ForwardingReferenceOverloadCheck.cpp
index 568f139bdb85..2f9946a7cc1b 100644
--- a/clang-tools-extra/clang-tidy/bugprone/ForwardingReferenceOverloadCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/ForwardingReferenceOverloadCheck.cpp
@@ -44,11 +44,12 @@ AST_MATCHER(QualType, isEnableIf) {
   if (CheckTemplate(BaseType->getAs<TemplateSpecializationType>()))
     return true; // Case: enable_if_t< >.
   if (const auto *Elaborated = BaseType->getAs<ElaboratedType>()) {
-    if (const auto *Qualifier = Elaborated->getQualifier()->getAsType()) {
-      if (CheckTemplate(Qualifier->getAs<TemplateSpecializationType>())) {
-        return true; // Case: enable_if< >::type.
+    if (const auto *Q = Elaborated->getQualifier())
+      if (const auto *Qualifier = Q->getAsType()) {
+        if (CheckTemplate(Qualifier->getAs<TemplateSpecializationType>())) {
+          return true; // Case: enable_if< >::type.
+        }
       }
-    }
   }
   return false;
 }
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/forwarding-reference-overload.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/forwarding-reference-overload.cpp
index 920029b56e55..38b0691bc9f1 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/forwarding-reference-overload.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/forwarding-reference-overload.cpp
@@ -240,3 +240,14 @@ public:
   Test9(const Test9 &other) = default;
   Test9(Test9 &&other) = default;
 };
+
+
+template <typename T>
+class Test10 {
+public:
+  enum E {};
+  E e;
+
+  Test10(T &&Item, E e)
+      : e(e){}
+};