Avoid adding null-objects to the icon cache

When we can't get the icon for the first time, we would use the data
in the cache later, and we will never get the new icon when the system
theme is updated while the application is running.

Pick-to: 6.1
Change-Id: I839ad9983918561a1dc6bc842f85477bba53f64a
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index 2b607ac5be..9c554dd513 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -1323,9 +1323,9 @@ QIcon QIcon::fromTheme(const QString &name)
         bool hasUserTheme = QIconLoader::instance()->hasUserTheme();
         QIconEngine * const engine = (platformTheme && !hasUserTheme) ? platformTheme->createIconEngine(name)
                                                    : new QIconLoaderEngine(name);
-        QIcon *cachedIcon  = new QIcon(engine);
-        icon = *cachedIcon;
-        qtIconCache()->insert(name, cachedIcon);
+        icon = QIcon(engine);
+        if (!icon.isNull())
+            qtIconCache()->insert(name, new QIcon(icon));
     }
 
     return icon;