Index: kernel/qasyncimageio.cpp
================================================================================
--- src/kernel/qasyncimageio.cpp
+++ src/kernel/qasyncimageio.cpp
@@ -901,7 +901,12 @@
 		    sheight = newtop + newheight;
 
 		if (img.isNull()) {
-		    img.create(swidth, sheight, 32);
+		    bool ok = img.create(swidth, sheight, 32);
+		    if (!ok)
+		    {
+			state = Error;
+			break;
+		    }
 		    memset( img.bits(), 0, img.numBytes() );
 		    if (consumer) consumer->setSize(swidth, sheight);
 		}
@@ -956,9 +961,15 @@
 		    if (backingstore.width() < w
 			|| backingstore.height() < h) {
 			// We just use the backing store as a byte array
-			backingstore.create( QMAX(backingstore.width(), w),
+			bool ok = backingstore.create(
+			                     QMAX(backingstore.width(), w),
 					     QMAX(backingstore.height(), h),
 					     32);
+			if (!ok)
+			{
+			    state = Error;
+			    break;
+			}
 			memset( img.bits(), 0, img.numBytes() );
 		    }
 		    for (int ln=0; ln<h; ln++) {
--- src/kernel/qimage.cpp
+++ src/kernel/qimage.cpp
@@ -65,6 +65,8 @@
 #define QT_NO_IMAGE_16_BIT
 #endif
 
+int qt_max_image_height = 0;
+int qt_max_image_width = 0;
 
 /*!
     \class QImage
@@ -1201,6 +1203,28 @@
     data->alpha = enable;
 }
 
+QSize QImage::maxImageSize()
+{
+    if (!qt_max_image_height || !qt_max_image_width)
+       return QSize();
+    return QSize(qt_max_image_height, qt_max_image_width);
+}
+
+void QImage::setMaxImageSize(const QSize &size)
+{
+    if (size.isValid())
+    {
+        qt_max_image_height = size.height();
+        qt_max_image_width = size.width();
+    }
+    else
+    {
+        qt_max_image_height = 0;
+        qt_max_image_width = 0;
+    }
+}
+
+
 
 /*!
     Sets the image \a width, \a height, \a depth, its number of colors
@@ -1230,6 +1254,14 @@
     reset();					// reset old data
     if ( width <= 0 || height <= 0 || depth <= 0 || numColors < 0 )
 	return FALSE;				// invalid parameter(s)
+    if ( qt_max_image_height && (height > qt_max_image_height * 4))
+        return FALSE; // Too high
+    if ( qt_max_image_width && (width > qt_max_image_width * 4))
+        return FALSE; // Too wide
+    if ( qt_max_image_height && qt_max_image_width &&
+         (height * width > qt_max_image_height * qt_max_image_width))
+        return FALSE; // Too large
+    
     if ( depth == 1 && bitOrder == IgnoreEndian ) {
 #if defined(QT_CHECK_RANGE)
 	qWarning( "QImage::create: Bit order is required for 1 bpp images" );
--- src/kernel/qimage.h
+++ src/kernel/qimage.h
@@ -194,6 +194,10 @@
 		      int quality=-1 ) const;
     bool	save( QIODevice * device, const char* format,
 		      int quality=-1 ) const;
+		      
+#define QT_HAVE_MAX_IMAGE_SIZE
+    static QSize maxImageSize();
+    static void setMaxImageSize(const QSize &size);
 #endif //QT_NO_IMAGEIO
 
     bool	valid( int x, int y ) const;