From a49d277e0da99f6585c0b94baee1c51afad69496 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Mon, 29 Jun 2020 13:09:01 +0200
Subject: [PATCH] Fixed #6471 (FP functionConst - member function modifying
 member variable after cast (inconclusive))

---
 lib/checkclass.cpp |  3 +++
 test/testclass.cpp | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 049c020bf..7300b8e29 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -1991,6 +1991,9 @@ bool CheckClass::checkConstFunc(const Scope *scope, const Function *func, bool&
             if (tok1->str() == "this" && tok1->previous()->isAssignmentOp())
                 return false;
 
+            // non const pointer cast
+            if (tok1->valueType() && tok1->valueType()->pointer > 0 && tok1->astParent() && tok1->astParent()->isCast() && !Token::simpleMatch(tok1->astParent(), "( const"))
+                return false;
 
             const Token* lhs = tok1->previous();
             if (lhs->str() == "&") {
diff --git a/test/testclass.cpp b/test/testclass.cpp
index 82d559000..a5db98b02 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -170,6 +170,7 @@ private:
         TEST_CASE(const65); // ticket #8693
         TEST_CASE(const66); // ticket #7714
         TEST_CASE(const67); // ticket #9193
+        TEST_CASE(const68); // ticket #6471
         TEST_CASE(const_handleDefaultParameters);
         TEST_CASE(const_passThisToMemberOfOtherClass);
         TEST_CASE(assigningPointerToPointerIsNotAConstOperation);
@@ -5514,6 +5515,17 @@ private:
         ASSERT_EQUALS("[test.cpp:8]: (style, inconclusive) Technically the member function 'Test::get' can be const.\n", errout.str());
     }
 
+    void const68() { // #6471
+        checkConst("class MyClass {\n"
+                   "    void clear() {\n"
+                   "        SVecPtr v = (SVecPtr) m_data;\n"
+                   "        v->clear();\n"
+                   "    }\n"
+                   "    void* m_data;\n"
+                   "};\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void const_handleDefaultParameters() {
         checkConst("struct Foo {\n"
                    "    void foo1(int i, int j = 0) {\n"