Bug 2138580

Description of problem:
5 CGNS desktop items with wrong icon and executable path. Visible in Xfce desktop session at: Applications -- Development
Problem not visible in GNOME desktop session, because CGNS desktop items not shown.

Version-Release number of selected component (if applicable):
cgnslib-common-4.2.0-4.fc35.noarch
cgnslib-common-4.2.0-6.fc36.noarch
cgnslib-common-4.3.0-2.fc37.noarch
cgnslib-common-4.3.0-1.el9.noarch

How reproducible:
easy and always

Steps to Reproduce:
1. for Fedora 36: install Xfce desktop environment: dnf group install -y xfce-desktop
   for CentOS Stream 9: dnf config-manager --set-enabled crb ; dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-9.noarch.rpm ; dnf group install -y Xfce ; systemctl set-default graphical ; reboot
2. dnf install -y cgnslib
3. reboot and log in to Xfce session
4. look at items in: Applications -- Development

Actual results:
5 items have:
* no icon (in desktop file icon uses relative path; pictures available in /usr/share/cgnstools)
* wrong path to executable (in desktop file the Exec value uses relative path, i.e. you cannot start program with GUI, you must use CLI; programs available in /usr/bin (which is in $PATH), but relative path starts in $HOME)
CGNScalc ; "./cgnscalc"
CGNSnodes ; "./cgnsnodes"
CGNSplot ; "./cgnsplot"
CGNSunitconv ; "./unitconv"
CGNSview ; "./cgnsview"

Expected results:
5 items use correct paths for icons and exectuables

Additional info:
Executables provided by:
$ rpm -qf /usr/bin/cgnsnodes ...
cgnslib-4.2.0-6.fc36.x86_64

Desktop files provided by cgnslib-common:
$ rpm -ql cgnslib-common
/usr/share/applications/cgnscalc.desktop
/usr/share/applications/cgnsnodes.desktop
/usr/share/applications/cgnsplot.desktop
/usr/share/applications/cgnsview.desktop
/usr/share/applications/unitconv.desktop
...


One example:
$ cat /usr/share/applications/cgnscalc.desktop
...
Exec="./cgnscalc"
Icon=../share/cgnstools/cgnscalc.png

It must be changed to:
Exec="cgnscalc"
Icon=/usr/share/cgnstools/cgnscalc.png


cgnslib-common not available on F34 and below, hence cgnslib-4.1.2-2.fc34 does not have the problem.
Ubuntu 22.04 LTS distributes CGNS 3.4 (no desktop shortcuts), hence I do not know if this problem is Fedora-specific. Let me know if I should report at upstream's issue tracker mentioned on: http://cgns.github.io/download.html