Screenshots are not correctly processed with 0.11.5

[antonio-rojas]

With appstream 0.11.5 the screenshot info is not correctly processed. For instance, for krita the xml produced by asgen contains

  <screenshot type="default">
    <image type="source" width="1916" height="1056">http://files.kde.org/krita/marketing/appdata/2016-05-24_screenshot_002.png</image>
  </screenshot>
  <screenshot type="default">
    <image type="source" width="1919" height="1056">http://files.kde.org/krita/marketing/appdata/2016-05-24_screenshot_003.png</image>
  </screenshot>
  <screenshot type="default">
    <image type="source" width="1921" height="1054">http://files.kde.org/krita/marketing/appdata/2016-05-24_screenshot_004.png</image>
  </screenshot>
  <screenshot type="default">
    <image type="source" width="1919" height="1052">http://files.kde.org/krita/marketing/appdata/2016-05-24_screenshot_005.png</image>
  </screenshot>

and 'appstreamcli dump org.kde.krita.desktop' doesn't output any screenshot info.

With previous appstream versions, the screenshot info in asgen-generated xml was enclosed in <screenshots>...</screenshots>:

  <screenshots>
    <screenshot type="default">
      <image type="source" width="1916" height="1056">http://files.kde.org/krita/marketing/appdata/2016-05-24_screenshot_002.png</image>
    </screenshot>
    <screenshot type="default">
      <image type="source" width="1919" height="1056">http://files.kde.org/krita/marketing/appdata/2016-05-24_screenshot_003.png</image>
    </screenshot>
    <screenshot type="default">
      <image type="source" width="1921" height="1054">http://files.kde.org/krita/marketing/appdata/2016-05-24_screenshot_004.png</image>
    </screenshot>
    <screenshot type="default">
      <image type="source" width="1919" height="1052">http://files.kde.org/krita/marketing/appdata/2016-05-24_screenshot_005.png</image>
    </screenshot>
  </screenshots>

and it was correctly processed and recognized by appstreamcli.

[ximion]

The metainfo data is wrong, there should never be more than one type="default" screenshot.
Regardless of that, there is a bug in the XML generator, I think I can fix it today.

[ximion]

This should be resolved by the patch above. The testsuite also checks screenshot writing (as opposed to only reading) now, so this or any other error does not happen again.