Increase the size of the image used as default cover

Better for modern high DPI monitors

imgsrc/default_cover.svg

@@ -2,21 +2,21 @@
 <!-- Created with Inkscape (http://www.inkscape.org/) -->
 
 <svg
-   xmlns:dc="http://purl.org/dc/elements/1.1/"
-   xmlns:cc="http://creativecommons.org/ns#"
-   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
-   xmlns:svg="http://www.w3.org/2000/svg"
-   xmlns="http://www.w3.org/2000/svg"
-   xmlns:xlink="http://www.w3.org/1999/xlink"
-   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
-   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
-   width="600"
-   height="800"
-   viewBox="0 0 600 800"
+   width="1200"
+   height="1600"
+   viewBox="0 0 1200 1600"
    id="svg2"
    version="1.1"
-   inkscape:version="0.91 r13725"
-   sodipodi:docname="default_cover.svg">
+   inkscape:version="1.2.1 (9c6d41e410, 2022-07-14)"
+   sodipodi:docname="default_cover.svg"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:xlink="http://www.w3.org/1999/xlink"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:dc="http://purl.org/dc/elements/1.1/">
   <defs
      id="defs4">
     <linearGradient
@@ -50,22 +50,25 @@
      borderopacity="1.0"
      inkscape:pageopacity="0.0"
      inkscape:pageshadow="2"
-     inkscape:zoom="1.979899"
-     inkscape:cx="143.72018"
-     inkscape:cy="392.41726"
+     inkscape:zoom="0.70000001"
+     inkscape:cx="448.57143"
+     inkscape:cy="567.14285"
      inkscape:document-units="px"
      inkscape:current-layer="svg2"
      showgrid="false"
      units="px"
      inkscape:window-width="3840"
-     inkscape:window-height="2128"
+     inkscape:window-height="2101"
      inkscape:window-x="0"
-     inkscape:window-y="32"
+     inkscape:window-y="59"
      inkscape:window-maximized="0"
      fit-margin-top="0"
      fit-margin-left="0"
      fit-margin-right="0"
-     fit-margin-bottom="0" />
+     fit-margin-bottom="0"
+     inkscape:showpageshadow="0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1" />
   <metadata
      id="metadata7">
     <rdf:RDF>
@@ -74,7 +77,6 @@
         <dc:format>image/svg+xml</dc:format>
         <dc:type
            rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
-        <dc:title></dc:title>
         <dc:creator>
           <cc:Agent>
             <dc:title>Kovid Goyal</dc:title>
@@ -91,10 +93,10 @@
           </cc:Agent>
         </dc:publisher>
         <cc:license
-           rdf:resource="http://creativecommons.org/licenses/by-sa/3.0/" />
+           rdf:resource="http://creativecommons.org/licenses/by-sa/4.0/" />
       </cc:Work>
       <cc:License
-         rdf:about="http://creativecommons.org/licenses/by-sa/3.0/">
+         rdf:about="http://creativecommons.org/licenses/by-sa/4.0/">
         <cc:permits
            rdf:resource="http://creativecommons.org/ns#Reproduction" />
         <cc:permits
@@ -112,7 +114,7 @@
   </metadata>
   <g
      id="g4150"
-     transform="matrix(6.6666667,0,0,6.6666667,-126.66667,-1040)">
+     transform="matrix(13.333333,0,0,13.333333,-253.33334,-2080)">
     <rect
        ry="0.89203537"
        y="156"

src/calibre/gui2/__init__.py

@@ -1258,7 +1258,9 @@ class Application(QApplication):
         ic = QIcon.ic(name)
         if not device_pixel_ratio:
             device_pixel_ratio = self.devicePixelRatio()
-        return ic.pixmap(r.size(), device_pixel_ratio)
+        ans = ic.pixmap(r.size())
+        ans.setDevicePixelRatio(device_pixel_ratio)
+        return ans
 
     def stylesheet_for_line_edit(self, is_error=False):
         return 'QLineEdit { border: 2px solid %s; border-radius: 3px }' % (