Add media type definition for exported certificate group files

GnuPG-bug-id: 5638

src/CMakeLists.txt

 add_subdirectory(icons)
+add_subdirectory(mimetypes)
 
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})

src/mimetypes/CMakeLists.txt

+# always install the media types
+install(FILES application-vnd-kde-kleopatra.xml DESTINATION ${XDG_MIME_INSTALL_DIR})
+
+# require at least version 1.3 (same as for KF5)
+find_package(SharedMimeInfo 1.3)
+set_package_properties(SharedMimeInfo PROPERTIES
+                       TYPE OPTIONAL
+                       PURPOSE "Enables import of exported certificate groups with Kleopatra"
+                      )
+
+# update XDG mime-types if shared mime info is around
+if(SharedMimeInfo_FOUND)
+    update_xdg_mimetypes(${XDG_MIME_INSTALL_DIR})
+endif()

src/mimetypes/XmlMessages.sh

+function get_files
+{
+    echo application-vnd-kde-kleopatra.xml
+}
+
+function po_for_file
+{
+    case "$1" in
+       application-vnd-kde-kleopatra.xml)
+           echo kleopatra_xml_mimetypes.po
+       ;;
+    esac
+}
+
+function tags_for_file
+{
+    case "$1" in
+       application-vnd-kde-kleopatra.xml)
+           echo comment
+       ;;
+    esac
+}
+

src/mimetypes/application-vnd-kde-kleopatra.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  SPDX-License-Identifier: CC0-1.0
+  SPDX-FileCopyrightText: 2021 g10 Code GmbH
+  SPDX-FileContributor: Ingo Klöcker <dev@ingo-kloecker.de>
+-->
+<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
+  <mime-type type="application/vnd.kde.kleopatra.keygroup">
+    <comment>Kleopatra certificate group</comment>
+    <sub-class-of type="text/plain"/>
+    <generic-icon name="text-x-generic"/>
+    <magic priority="80">
+      <match type="string" value="[KeyGroup-" offset="0"/>
+    </magic>
+    <glob pattern="*.kgrp"/>
+  </mime-type>
+</mime-info>