Make sure QIconLoader is always initialized

It is necessary to properly initialize the icon loader in all case.
Otherwise some calls might give wrong results if a platform theme plugin
is involved.
For instance, we might miss the actual theme name reported by the
platform theme, eg it's what happen with QStyle::standardPixmap if no
one created a QIcon before its first call.

Also clean up the accesses to the global static and have only
QIconLoader::instance() use it. All other call go through the static
method. This way only instance() needs to call ensureInitialized(),
definitely safer and looks cleaner to me.

Change-Id: Id3ea6816edd5a65586004f69464960abc3602cf8
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

2 files changed, 5 insertions, 8 deletions

diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index d73cd0aa57..ea35da54dc 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -1063,7 +1063,6 @@ void QIcon::setThemeName(const QString &name)
 */
 QString QIcon::themeName()
 {
-    QIconLoader::instance()->ensureInitialized();
     return QIconLoader::instance()->themeName();
 }
 
diff --git a/src/gui/image/qiconloader.cpp b/src/gui/image/qiconloader.cpp
index c2e5161bd3..6303f5cbe1 100644
--- a/src/gui/image/qiconloader.cpp
+++ b/src/gui/image/qiconloader.cpp
@@ -127,6 +127,7 @@ void QIconLoader::ensureInitialized()
 
 QIconLoader *QIconLoader::instance()
 {
+   iconLoaderInstance()->ensureInitialized();
    return iconLoaderInstance();
 }
 
@@ -367,17 +368,14 @@ bool QIconLoaderEngine::hasIcon() const
 // Lazily load the icon
 void QIconLoaderEngine::ensureLoaded()
 {
-
-    iconLoaderInstance()->ensureInitialized();
-
-    if (!(iconLoaderInstance()->themeKey() == m_key)) {
+    if (!(QIconLoader::instance()->themeKey() == m_key)) {
 
         while (!m_entries.isEmpty())
             delete m_entries.takeLast();
 
         Q_ASSERT(m_entries.size() == 0);
-        m_entries = iconLoaderInstance()->loadIcon(m_iconName);
-        m_key = iconLoaderInstance()->themeKey();
+        m_entries = QIconLoader::instance()->loadIcon(m_iconName);
+        m_key = QIconLoader::instance()->themeKey();
     }
 }
 
@@ -564,7 +562,7 @@ void QIconLoaderEngine::virtual_hook(int id, void *data)
         {
             QIconEngine::AvailableSizesArgument &arg
                     = *reinterpret_cast<QIconEngine::AvailableSizesArgument*>(data);
-            const QList<QIconDirInfo> directoryKey = iconLoaderInstance()->theme().keyList();
+            const QList<QIconDirInfo> directoryKey = QIconLoader::instance()->theme().keyList();
             arg.sizes.clear();
 
             // Gets all sizes from the DirectoryInfo entries