Fixed #4367 (false positive: Class '...' is unsafe, '...' can leak by wrong usage)

lib/checkmemoryleak.cpp

@@ -2380,10 +2380,15 @@ void CheckMemoryLeakInClass::variable(const Scope *scope, const Token *tokVarnam
     // Inspect member functions
     std::list<Function>::const_iterator func;
     for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
-        if (!func->hasBody)
-            continue;
         const bool constructor = func->type == Function::eConstructor;
         const bool destructor = func->type == Function::eDestructor;
+        if (!func->hasBody) {
+            if (destructor) { // implementation for destructor is not seen => assume it deallocates all variables properly
+                deallocInDestructor = true;
+                Dealloc = CheckMemoryLeak::Many;
+            }
+            continue;
+        }
         bool body = false;
         const Token *end = func->functionScope->classEnd;
         for (const Token *tok = func->arg->link(); tok != end; tok = tok->next()) {

test/testmemleak.cpp

@@ -3935,6 +3935,7 @@ private:
         TEST_CASE(class22); // ticket #3012
         TEST_CASE(class23); // ticket #3303
         TEST_CASE(class24); // ticket #3806 - false positive in copy constructor
+        TEST_CASE(class25); // ticket #4367 - false positive implementation for destructor is not seen
 
         TEST_CASE(staticvar);
 
@@ -4848,6 +4849,17 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void class25() { // ticket #4367 - false positive when implementation for destructor is not seen
+        check("class Fred {\n"
+              "private:\n"
+              "    int * a;\n"
+              "public:\n"
+              "    Fred() { a = new int; }\n"
+              "    ~Fred();\n"
+              "};\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void staticvar() {
         check("class A\n"
               "{\n"