https://github.com/BestImageViewer/geeqie/pull/742
Set installation folder location dependent on $prefix variable.
(Flatpak installation requires to the location to be not where
freedesktop.org defines it)
icon_DATA = geeqie.png
# Location defined by freedesktop.org
+if EXTERNAL_PREFIX
+appdatadir = $(datadir)/metainfo
+else
appdatadir = /usr/share/metainfo
+endif
appdata_DATA = $(appdata_in_files:.xml.in=.xml)
appdata_in_files = org.geeqie.Geeqie.appdata.xml.in
@INTLTOOL_XML_RULE@
AM_CONDITIONAL(HAVE_WINDRES, test "x$WINDRES" != "x:")
AC_SUBST(WINDRES)
+AM_CONDITIONAL([EXTERNAL_PREFIX], [test "x$prefix" != "xNONE"])
+
dnl reasonable guesses for where stuff is installed
if test "x$prefix" = "xNONE"; then
prefix="/usr/local"