use QFile::open()'s return value instead of using weird isOpen() checks

src/plugins/qmldesigner/components/propertyeditor/basicwidgets.cpp

@@ -443,8 +443,7 @@ public:
         else
             fileName = (_styleSheetFile.toLocalFile());
         QFile file(fileName);
-        file.open(QIODevice::ReadOnly);
-        if (file.isOpen()) {
+        if (file.open(QIODevice::ReadOnly)) {
             QString styleSheet(file.readAll());
             q->setStyleSheet(styleSheet);
         } else {
@@ -634,8 +633,7 @@ private:
         }
 
         QFile file(path);
-        file.open(QIODevice::ReadOnly);
-        if (file.exists() && file.isOpen()) {
+        if (file.open(QIODevice::ReadOnly)) {
             QPixmap pixmap(path);
             if (pixmap.isNull())
                 qWarning() << QLatin1String("setIconFromFile: ") << url << QLatin1String(" not found!");
@@ -700,8 +698,7 @@ private:
         }
 
         QFile file(path);
-        file.open(QIODevice::ReadOnly);
-        if (file.exists() && file.isOpen()) {
+        if (file.open(QIODevice::ReadOnly)) {
             QPixmap pixmap(path);
             if (pixmap.isNull())
                 qWarning() << QLatin1String("setIconFromFile: ") << url << QLatin1String(" not found!");
@@ -773,8 +770,7 @@ private:
         }
 
         QFile file(path);
-        file.open(QIODevice::ReadOnly);
-        if (file.exists() && file.isOpen()) {
+        if (file.open(QIODevice::ReadOnly)) {
             QPixmap pixmap(path);
             if (pixmap.isNull())
                 qWarning() << QLatin1String("setIconFromFile: ") << url << QLatin1String(" not found!");

src/plugins/qmldesigner/components/propertyeditor/layoutwidget.cpp

@@ -94,8 +94,7 @@ LayoutWidget::~LayoutWidget()
  {
         if (url.scheme() == QLatin1String("file")) {
             QFile file(url.toLocalFile());
-            file.open(QIODevice::ReadOnly);
-            if (file.isOpen()) {
+            if (file.open(QIODevice::ReadOnly)) {
                 QPixmap pixmap(url.toLocalFile());
                 button->setIcon(pixmap);
             } else {