fix #2637 (segmentation fault of cppcheck ( {} const const ))

lib/symboldatabase.cpp

@@ -1467,6 +1467,9 @@ void Scope::getVariableList()
             continue;
 
         tok = checkVariable(tok, varaccess);
+
+        if (!tok)
+            break;
     }
 }
 
@@ -1515,7 +1518,7 @@ const Token *Scope::checkVariable(const Token *tok, AccessControl varaccess)
 
     bool isArray = false;
 
-    if (isVariableDeclaration(tok, vartok, typetok, isArray))
+    if (tok && isVariableDeclaration(tok, vartok, typetok, isArray))
     {
         isClass = (!typetok->isStandardType() && vartok->previous()->str() != "*");
         tok = vartok->next();

test/testclass.cpp

@@ -196,6 +196,7 @@ private:
         TEST_CASE(symboldatabase13); // ticket #2577
         TEST_CASE(symboldatabase14); // ticket #2589
         TEST_CASE(symboldatabase15); // ticket #2591
+        TEST_CASE(symboldatabase16); // ticket #2637
     }
 
     // Check the operator Equal
@@ -5791,6 +5792,14 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void symboldatabase16()
+    {
+        // ticket #2637 - segmentation fault
+        checkConst("{} const const\n");
+
+        ASSERT_EQUALS("", errout.str());
+    }
+
 };
 
 REGISTER_TEST(TestClass)