Bug 1216218

That's weird. exo does not even ship an appdata file. I thought GNOME software showed only those items that shipped appdata files.

$ rpm -ql exo | grep -i app
/usr/bin/exo-preferred-applications
/usr/share/applications/exo-file-manager.desktop
/usr/share/applications/exo-mail-reader.desktop
/usr/share/applications/exo-preferred-applications.desktop
/usr/share/applications/exo-terminal-emulator.desktop
/usr/share/applications/exo-web-browser.desktop
/usr/share/icons/hicolor/24x24/apps/internet-mail.png
/usr/share/icons/hicolor/24x24/apps/preferences-desktop-default-applications.png
/usr/share/icons/hicolor/48x48/apps/internet-mail.png
/usr/share/icons/hicolor/48x48/apps/preferences-desktop-default-applications.png
/usr/share/icons/hicolor/48x48/categories/applications-internet.png
/usr/share/icons/hicolor/48x48/categories/applications-other.png


I will install GNOME in a VM and try to track this. 

Thanks for the report. The described behavior is indeed very unfortunate.

Well I did this on Xfce, not GNOME.

Also happens on F21.


$ zcat /usr/share/app-info/xmls/fedora-21.xml.gz | grep '<name>Web Browser' -B3 -A156
  <component type="desktop">
    <id>exo-web-browser.desktop</id>
    <pkgname>exo</pkgname>
    <name>Web Browser</name>
    <name xml:lang="ar">متصفّح وِب</name>
    ...
    <name xml:lang="zh_TW">網路瀏覽器</name>
    <summary>Browse the web</summary>
    <summary xml:lang="ar">تصفح الوِب</summary>
    ...
    <summary xml:lang="zh_TW">瀏覽網路</summary>
    <icon type="stock">web-browser</icon>
    <categories>
      <category>Network</category>
    </categories>
    <kudos>
      <kudo>HiDpiIcon</kudo>
    </kudos>
    <project_license>LGPL-2.1+ AND GPL-2.0+</project_license>
    <url type="homepage">http://xfce.org/</url>
    <project_group>XFCE</project_group>
    <releases>
      <release version="0.10.2" timestamp="1356609600"/>
      <release version="0.10.1" timestamp="1355054400"/>
      <release version="0.10.0" timestamp="1354622400"/>
    </releases>
    <languages>
      <lang percentage="100">ar</lang>
      ...
      <lang percentage="100">zh_TW</lang>
    </languages>
    <metadata>
      <value key="X-CacheID">exo-0.10.2-8.fc21.x86_64.rpm</value>
    </metadata>
  </component>

Looks like parsed from the desktop file for default web browser in Xfce.

$ rpm -qf /usr/share/app-info/xmls/fedora-21.xml.gz
appstream-data-21-20.fc21.noarch

$ rpm -qf /usr/share/app-info/xmls/fedora-22.xml.gz
appstream-data-22-7.fc22.noarch

libappstream-glib-0.3.6-2.fc22 has been submitted as an update for Fedora 22.
https://admin.fedoraproject.org/updates/libappstream-glib-0.3.6-2.fc22

FYI, this was a typo in the appstream data. It should have been blacklisted all along... 

https://github.com/hughsie/appstream-glib/commit/110218325c2f914ee88f2f52341692f518f2e367

Thanks, could you also update this in F21?

Package libappstream-glib-0.3.6-2.fc22:
* should fix your issue,
* was pushed to the Fedora 22 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing libappstream-glib-0.3.6-2.fc22'
as soon as you are able to.
Please go to the following url:
https://admin.fedoraproject.org/updates/FEDORA-2015-7252/libappstream-glib-0.3.6-2.fc22
then log in and leave karma (feedback).

libappstream-glib-0.3.6-2.fc22 has been pushed to the Fedora 22 stable repository.  If problems still persist, please make note of it in this bug report.

gnome-software-3.14.5-2.fc21, PackageKit-1.0.6-1.fc21, libhif-0.2.0-3.fc21, libappstream-glib-0.4.0-1.fc21 has been submitted as an update for Fedora 21.
https://admin.fedoraproject.org/updates/FEDORA-2015-9570/gnome-software-3.14.5-2.fc21,PackageKit-1.0.6-1.fc21,libhif-0.2.0-3.fc21,libappstream-glib-0.4.0-1.fc21

gnome-software-3.14.5-2.fc21, PackageKit-1.0.6-1.fc21, libhif-0.2.0-3.fc21, libappstream-glib-0.4.0-1.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.