qt.conf ignored when QImageReader::supportedImageFormats is called in static scope

I'm not sure if this will ultimately be considered a bug but at the very least a warning should be added to the documentation on qt.conf as this is a very dangerous gotcha.

An example is below. If this code is run, QLibraryInfo::location will report the installed location of the Qt libraries it was compiled against every time regardless of the contents of qt.conf. If QImageReader::supportedImageFormats() is not called, it will load properly from the qt.conf packaged in the resource system.

I suspect there are other functions that could be called that would produce the same error.

#include <QtGui/QApplication>

#include <QFile>
#include <QStringList>
#include <QDebug>
#include <QLibraryInfo>
#include <QImageReader>

QList<QByteArray> formats = QImageReader::supportedImageFormats();

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    qDebug() << "qt.conf " << QFile::exists(QLatin1String(":/qt/etc/qt.conf"));
    qDebug() << "LIBRARIES LOADED: " << QCoreApplication::libraryPaths();
    qDebug() << "PREFIX PATH" << QLibraryInfo::location(QLibraryInfo::PrefixPath);
    qDebug() << "PLUGINS PATH" << QLibraryInfo::location(QLibraryInfo::PluginsPath);

    qDebug() << formats.size() << " image formats supported";

    return 0;
}

Example bad output(same qt.conf file as the good output):

qt.conf  true 
LIBRARIES LOADED:  ("/Users/ebrenner/QtSDK/Desktop/Qt/4.8.1/gcc/plugins", "/Users/ebrenner/QtProjects/QtConfTest_Qt_4_8_1_release/QtConfTest.app/Contents/MacOS") 
PREFIX PATH "/Users/ebrenner/QtSDK/Desktop/Qt/4.8.1/gcc" 
PLUGINS PATH "/Users/ebrenner/QtSDK/Desktop/Qt/4.8.1/gcc/plugins" 
17  image formats supported 

Example good output(formats is initialized with the default constructor and qt.conf sets prefix to .):

qt.conf  true 
LIBRARIES LOADED:  ("/Users/ebrenner/QtProjects/QtConfTest_Qt_4_8_1_release/QtConfTest.app/Contents/MacOS") 
PREFIX PATH "/Users/ebrenner/QtProjects/QtConfTest_Qt_4_8_1_release/QtConfTest.app/Contents" 
PLUGINS PATH "/Users/ebrenner/QtProjects/QtConfTest_Qt_4_8_1_release/QtConfTest.app/Contents/plugins" 
0  image formats supported