Fixed #6968 (unusedPrivateFunction not correct, called by inner class)

lib/checkclass.cpp

@@ -899,10 +899,10 @@ static bool checkFunctionUsage(const Function *privfunc, const Scope* scope)
             return true;
     }
 
-    for (std::list<Scope*>::const_iterator i = scope->nestedList.begin(); i != scope->nestedList.end(); ++i) {
-        if ((*i)->isClassOrStruct())
-            if (checkFunctionUsage(privfunc, *i)) // Check nested classes, which can access private functions of their base
-                return true;
+    for (std::list<Type*>::const_iterator i = scope->definedTypes.begin(); i != scope->definedTypes.end(); ++i) {
+        const Type *type = *i;
+        if (type->enclosingScope == scope && checkFunctionUsage(privfunc, type->classScope))
+            return true;
     }
 
     for (std::list<Variable>::const_iterator i = scope->varlist.begin(); i != scope->varlist.end(); ++i) {

test/testunusedprivfunc.cpp

@@ -392,6 +392,17 @@ private:
               "    };\n"
               "};");
         ASSERT_EQUALS("", errout.str());
+
+        check("class A {\n"  // #6968 - outer definition
+              "public:\n"
+              "  class B;\n"
+              "private:\n"
+              "  void f() {}\n"
+              "}\n"
+              "class A::B {"
+              "  B() { A a; a.f(); }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }