Fix #5889 (version 0.7.3 for Macintosh - ZeroDivisionError:float division)

src/calibre/ebooks/epub/output.py

@@ -84,7 +84,7 @@ class EPUBOutput(OutputFormatPlugin):
 
         OptionRecommendation(name='no_svg_cover', recommended_value=False,
             help=_('Do not use SVG for the book cover. Use this option if '
-                'your EPUB is going to be used ona  device that does not '
+                'your EPUB is going to be used on a device that does not '
                 'support SVG, like the iPhone or the JetBook Lite. '
                 'Without this option, such devices will display the cover '
                 'as a blank page.')

src/calibre/gui2/book_details.py

@@ -93,6 +93,8 @@ class CoverView(QWidget): # {{{
         self._current_pixmap_size = val
 
     def do_layout(self):
+        if self.rect().width() == 0 or self.rect().height() == 0:
+            return
         pixmap = self.pixmap
         pwidth, pheight = pixmap.width(), pixmap.height()
         self.pwidth, self.pheight = fit_image(pwidth, pheight,