Fix possible null pointer dereferences.

This follows up 130c2baa9376dcf525916620294bd9996bdf41f3.

Change-Id: I2f6c9b4f995af427cec9a2162b782039debf8564
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@theqtcompany.com>

2 files changed, 23 insertions, 0 deletions

diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index b2d9ed18f5..dc6cbfed1f 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -1208,6 +1208,12 @@ bool QIcon::hasThemeIcon(const QString &name)
 */
 void QIcon::setIsMask(bool isMask)
 {
+    if (!d) {
+        d = new QIconPrivate;
+        d->engine = new QPixmapIconEngine;
+    } else {
+        detach();
+    }
     d->is_mask = isMask;
 }
 
@@ -1222,6 +1228,8 @@ void QIcon::setIsMask(bool isMask)
 */
 bool QIcon::isMask() const
 {
+    if (!d)
+        return false;
     return d->is_mask;
 }
 
diff --git a/tests/auto/gui/image/qicon/tst_qicon.cpp b/tests/auto/gui/image/qicon/tst_qicon.cpp
index 9ed3873682..7333dd739f 100644
--- a/tests/auto/gui/image/qicon/tst_qicon.cpp
+++ b/tests/auto/gui/image/qicon/tst_qicon.cpp
@@ -53,6 +53,7 @@ private slots:
     void actualSize2_data(); // test with 2 pixmaps with different aspect ratio
     void actualSize2();
     void isNull();
+    void isMask();
     void swap();
     void bestMatch();
     void cacheKey();
@@ -218,6 +219,20 @@ void tst_QIcon::isNull() {
     QVERIFY(iconSupportedFormat.actualSize(QSize(32, 32)).isValid());
 }
 
+void tst_QIcon::isMask()
+{
+    QIcon icon;
+    icon.setIsMask(true);
+    icon.addPixmap(QPixmap());
+    QVERIFY(icon.isMask());
+
+    QIcon icon2;
+    icon2.setIsMask(true);
+    QVERIFY(icon2.isMask());
+    icon2.setIsMask(false);
+    QVERIFY(!icon2.isMask());
+}
+
 void tst_QIcon::swap()
 {
     QPixmap p1(1, 1), p2(2, 2);