[analyzer] DynamicTypeInfo: Avoid putting null regions into dynamic typemap.

Fixes a crash.

llvm-svn: 369726

clang/lib/StaticAnalyzer/Core/DynamicType.cpp

@@ -93,6 +93,9 @@ ProgramStateRef setDynamicTypeAndCastInfo(ProgramStateRef State,
                                           QualType CastFromTy,
                                           QualType CastToTy, QualType ResultTy,
                                           bool CastSucceeds) {
+  if (!MR)
+    return State;
+
   if (CastSucceeds)
     State = State->set<DynamicTypeMap>(MR, ResultTy);
 

clang/test/Analysis/cast-value-logic.cpp

@@ -131,3 +131,8 @@ void evalLogic(const Shape *S) {
 }
 } // namespace test_get_as
 
+namespace crashes {
+void test_non_reference_null_region_crash(Shape s) {
+  cast<Circle>(s); // no-crash
+}
+} // namespace crashes