Fix FP leakNoVarFunctionCall with Qt object (#4272)

* Add missing <leak-ignore/>, test

* Fix qt.cfg, format

* Fix FP leakNoVarFunctionCall

* Format

* Delete memory, rule of five

* Missing include

* Avoid dependency

* explicit

* Fix Qt test case

* Fix typo

* Fix

* Add Q_OBJECT

Author: chrchr-github

cfg/qt.cfg

@@ -383,6 +383,7 @@
   <!-- QMetaObject::Connection QObject::connect(const QObject *sender, PointerToMemberFunction signal, const QObject *context, Functor functor, Qt::ConnectionType type = Qt::AutoConnection) // static -->
   <function name="connect,QObject::connect">
     <noreturn>false</noreturn>
+    <leak-ignore/>	  
     <arg nr="1" direction="in">
       <not-null/>
       <not-uninit/>
@@ -414,6 +415,7 @@
   <!-- bool QObject::disconnect(const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method) // static -->
   <function name="disconnect,QObject::disconnect">
     <noreturn>false</noreturn>
+    <leak-ignore/>
     <arg nr="1" direction="in">
       <not-null/>
       <not-uninit/>
@@ -445,6 +447,7 @@
   <function name="QMenu::addAction">
     <noreturn>false</noreturn>
     <returnValue type="QAction *"/>
+    <leak-ignore/>
     <arg nr="1" direction="in">
       <not-uninit/>
       <not-bool/>

gui/helpdialog.cpp

@@ -112,4 +112,5 @@ HelpDialog::HelpDialog(QWidget *parent) :
 HelpDialog::~HelpDialog()
 {
     delete mUi;
+    delete mHelpEngine;
 }

gui/helpdialog.h

@@ -33,6 +33,10 @@ namespace Ui {
 class HelpBrowser : public QTextBrowser {
 public:
     explicit HelpBrowser(QWidget* parent = nullptr) : QTextBrowser(parent), mHelpEngine(nullptr) {}
+    HelpBrowser(const HelpBrowser&) = delete;
+    HelpBrowser(HelpBrowser&&) = delete;
+    HelpBrowser& operator=(const HelpBrowser&) = delete;
+    HelpBrowser& operator=(HelpBrowser&&) = delete;
     void setHelpEngine(QHelpEngine *helpEngine);
     QVariant loadResource(int type, const QUrl& name) override;
 private:

lib/checkmemoryleak.cpp

@@ -1027,7 +1027,10 @@ void CheckMemoryLeakNoVar::checkForUnreleasedInputArgument(const Scope *scope)
                     break;
                 arg = arg->astOperand1();
             }
-            if (getAllocationType(arg, 0) == No)
+            const AllocType alloc = getAllocationType(arg, 0);
+            if (alloc == No)
+                continue;
+            if ((alloc == New || alloc == NewArray) && arg->next() && !(arg->next()->isStandardType() || mSettings->library.detectContainerOrIterator(arg)))
                 continue;
             if (isReopenStandardStream(arg))
                 continue;

test/cfg/qt.cpp

@@ -470,3 +470,20 @@ void nullPointer(int * pIntPtr)
         *pIntPtr = 3;
     }
 }
+
+namespace {
+    class C : public QObject {
+        Q_OBJECT
+    public:
+        explicit C(QObject* parent = nullptr) : QObject(parent) {}
+        void signal() {}
+    };
+    class D : public QObject {
+        Q_OBJECT
+    public:
+        D() {
+            connect(new C(this), &C::signal, this, &D::slot);
+        }
+        void slot() {};
+    };
+}