check for the data pointer, not for the size

this way we can load resources of 0 bytes (not much useful per-se, but at least we know they are actually existing in the epub archive)

svn path=/trunk/KDE/kdegraphics/okular/; revision=1182899

generators/epub/converter.cpp

@@ -190,7 +190,7 @@ QTextDocument* Converter::convert( const QString &fileName )
         } else { // load missing resource
           char *data;
           int size = epub_get_data(mTextDocument->getEpub(), clink, &data);
-          if (size > 0) {
+          if (data) {
             _cursor->insertBlock();
 
             // try to load as image and if not load as html

generators/epub/epubdocument.cpp

@@ -61,7 +61,7 @@ QVariant EpubDocument::loadResource(int type, const QUrl &name)
 
   QVariant resource;
 
-  if (size > 0) {
+  if (data) {
     switch(type) {
     case QTextDocument::ImageResource:
       resource.setValue(QImage::fromData((unsigned char *)data, size));