From ff1c12376ba2a99be50d34f0c6a7ac9afd725b10 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@kdab.com>
Date: Mon, 1 Jun 2020 11:54:45 +0200
Subject: [PATCH] QPainter: replace manual memory management [4/5]:
 emulationEngine
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Use unique_ptr to indicate ownership.

The QPainter dtor is now empty, = default it.

As a drive-by, fix a non-sensical if (p) p = nullptr;

Change-Id: I5c811eb7de6abf8a9f279cf3630d5f86db6b3864
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 src/gui/painting/qpainter.cpp | 27 +++++++--------------------
 src/gui/painting/qpainter_p.h |  2 +-
 2 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 6a0d431a50..82a96960a8 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -206,29 +206,24 @@ void QPainterPrivate::checkEmulation()
         return;
 
     if (doEmulation) {
-        if (extended != emulationEngine) {
+        if (extended != emulationEngine.get()) {
             if (!emulationEngine)
-                emulationEngine = new QEmulationPaintEngine(extended);
-            extended = emulationEngine;
+                emulationEngine = std::make_unique<QEmulationPaintEngine>(extended);
+            extended = emulationEngine.get();
             extended->setState(state.get());
         }
-    } else if (emulationEngine == extended) {
+    } else if (emulationEngine.get() == extended) {
         extended = emulationEngine->real_engine;
     }
 }
 
-
 QPainterPrivate::QPainterPrivate(QPainter *painter)
     : q_ptr(painter), txinv(0), inDestructor(false)
 {
-
 }
 
 QPainterPrivate::~QPainterPrivate()
-{
-    delete emulationEngine;
-}
-
+    = default;
 
 QTransform QPainterPrivate::viewTransform() const
 {
@@ -346,7 +341,6 @@ void QPainterPrivate::detachPainterPrivate(QPainter *q)
 
     if (emulationEngine) {
         extended = emulationEngine->real_engine;
-        delete emulationEngine;
         emulationEngine = nullptr;
     }
 }
@@ -1918,15 +1912,8 @@ bool QPainter::end()
     }
 
     d->engine.reset();
-
-    if (d->emulationEngine) {
-        delete d->emulationEngine;
-        d->emulationEngine = nullptr;
-    }
-
-    if (d->extended) {
-        d->extended = nullptr;
-    }
+    d->emulationEngine = nullptr;
+    d->extended = nullptr;
 
     qt_cleanup_painter_state(d);
 
diff --git a/src/gui/painting/qpainter_p.h b/src/gui/painting/qpainter_p.h
index c369922756..09de84f2b2 100644
--- a/src/gui/painting/qpainter_p.h
+++ b/src/gui/painting/qpainter_p.h
@@ -272,7 +272,7 @@ public:
     };
     std::unique_ptr<QPaintEngine, QPaintEngineDestructor> engine;
 
-    QEmulationPaintEngine *emulationEngine = nullptr;
+    std::unique_ptr<QEmulationPaintEngine> emulationEngine;
     QPaintEngineEx *extended = nullptr;
     QBrush colorBrush;          // for fill with solid color
 };