From c72c22871774261ad980eb5a7e0c786ee44a5a4d Mon Sep 17 00:00:00 2001
From: Volker Hilsheimer <volker.hilsheimer@qt.io>
Date: Thu, 25 Feb 2021 16:58:27 +0100
Subject: [PATCH] Add nullptr checks to QGraphicsView classes

The styleInfo parameter defaults to nullptr, and the scene can evidently
be nullptr since we test for it before ungrabbing the mouse.

Fixes static analyzer warnings
fbd03604cc701651595a2ea33c5562b4 and
30fcb05194f3a2d121fc57b05e0ccf10

Change-Id: I8e9d4fe4055115c366ada1cbb22a8f0839ba41da
Reviewed-by: David Skoland <david.skoland@qt.io>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
(cherry picked from commit 98db99657649d4668c766eaa36b8d29c58d19754)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 .../graphicsview/qgraphicsanchorlayout_p.cpp  |  4 +-
 src/widgets/graphicsview/qgraphicsitem.cpp    | 38 ++++++++++---------
 2 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/src/widgets/graphicsview/qgraphicsanchorlayout_p.cpp b/src/widgets/graphicsview/qgraphicsanchorlayout_p.cpp
index be26b2785e3..9da290974b5 100644
--- a/src/widgets/graphicsview/qgraphicsanchorlayout_p.cpp
+++ b/src/widgets/graphicsview/qgraphicsanchorlayout_p.cpp
@@ -225,7 +225,7 @@ void AnchorData::refreshSizeHints(const QLayoutStyleInfo *styleInfo)
         if (anchorPrivate->hasSize) {
             // Anchor has user-defined size
             prefSizeHint = anchorPrivate->preferredSize;
-        } else {
+        } else if (styleInfo) {
             // Fetch size information from style
             const Qt::Orientation orient = QGraphicsAnchorLayoutPrivate::edgeOrientation(from->m_edge);
             qreal s = styleInfo->defaultSpacing(orient);
@@ -241,6 +241,8 @@ void AnchorData::refreshSizeHints(const QLayoutStyleInfo *styleInfo)
                     s = 0;
             }
             prefSizeHint = s;
+        } else {
+            prefSizeHint = 0;
         }
     }
 
diff --git a/src/widgets/graphicsview/qgraphicsitem.cpp b/src/widgets/graphicsview/qgraphicsitem.cpp
index e426e09adf7..bad40b0cffd 100644
--- a/src/widgets/graphicsview/qgraphicsitem.cpp
+++ b/src/widgets/graphicsview/qgraphicsitem.cpp
@@ -2652,23 +2652,25 @@ void QGraphicsItemPrivate::setEnabledHelper(bool newEnabled, bool explicitly, bo
 
     // Certain properties are dropped when an item is disabled.
     if (!newEnabled) {
-        if (scene && scene->mouseGrabberItem() == q_ptr)
-            q_ptr->ungrabMouse();
-        if (q_ptr->hasFocus()) {
-            // Disabling the closest non-panel ancestor of the focus item
-            // causes focus to pop to the next item, otherwise it's cleared.
-            QGraphicsItem *focusItem = scene->focusItem();
-            bool clear = true;
-            if (isWidget && !focusItem->isPanel() && q_ptr->isAncestorOf(focusItem)) {
-                do {
-                    if (focusItem == q_ptr) {
-                        clear = !static_cast<QGraphicsWidget *>(q_ptr)->focusNextPrevChild(true);
-                        break;
-                    }
-                } while ((focusItem = focusItem->parentWidget()) && !focusItem->isPanel());
+        if (scene) {
+            if (scene->mouseGrabberItem() == q_ptr)
+                q_ptr->ungrabMouse();
+            if (q_ptr->hasFocus()) {
+                // Disabling the closest non-panel ancestor of the focus item
+                // causes focus to pop to the next item, otherwise it's cleared.
+                QGraphicsItem *focusItem = scene->focusItem();
+                bool clear = true;
+                if (isWidget && !focusItem->isPanel() && q_ptr->isAncestorOf(focusItem)) {
+                    do {
+                        if (focusItem == q_ptr) {
+                            clear = !static_cast<QGraphicsWidget *>(q_ptr)->focusNextPrevChild(true);
+                            break;
+                        }
+                    } while ((focusItem = focusItem->parentWidget()) && !focusItem->isPanel());
+                }
+                if (clear)
+                    q_ptr->clearFocus();
             }
-            if (clear)
-                q_ptr->clearFocus();
         }
         if (q_ptr->isSelected())
             q_ptr->setSelected(false);
@@ -7149,14 +7151,14 @@ void QGraphicsItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
             if ((item->flags() & ItemIsMovable) && !QGraphicsItemPrivate::movableAncestorIsSelected(item)) {
                 QPointF currentParentPos;
                 QPointF buttonDownParentPos;
-                if (item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorIgnoresTransformations) {
+                if (view && (item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorIgnoresTransformations)) {
                     // Items whose ancestors ignore transformations need to
                     // map screen coordinates to local coordinates, then map
                     // those to the parent.
                     QTransform viewToItemTransform = (item->deviceTransform(view->viewportTransform())).inverted();
                     currentParentPos = mapToParent(viewToItemTransform.map(QPointF(view->mapFromGlobal(event->screenPos()))));
                     buttonDownParentPos = mapToParent(viewToItemTransform.map(QPointF(view->mapFromGlobal(event->buttonDownScreenPos(Qt::LeftButton)))));
-                } else if (item->flags() & ItemIgnoresTransformations) {
+                } else if (view && (item->flags() & ItemIgnoresTransformations)) {
                     // Root items that ignore transformations need to
                     // calculate their diff by mapping viewport coordinates
                     // directly to parent coordinates.