Close #552: issues with icons in gnome dock

coreApp->setOrganizationDomain() expects the domain
in DNS order (hohnstaedt.de) and not reversed.

Change the WM_CLASS property to "de.hohnstaedt.xca"
via setApplicationName().
While Qt6 prepends the reversed "OrganizationDomain",
Qt5 does not and setting the complete name with
domain-prefix works for both.

Also adopt the ".desktop" file name to follow the application-name
and fix issues found by "desktop-file-validate"

lib/main.cpp

@@ -142,8 +142,8 @@ int main(int argc, char *argv[])
 	UI_method_set_writer(uimeth.data(), uiwriter);
 	UI_set_default_method(uimeth.data());
 
-	coreApp->setApplicationName(PACKAGE_TARNAME);
-	coreApp->setOrganizationDomain("de.hohnstaedt");
+	coreApp->setApplicationName("de.hohnstaedt.xca");
+	coreApp->setOrganizationDomain("hohnstaedt.de");
 	coreApp->setApplicationVersion(XCA_VERSION);
 	xcaWarning::setGui(new xcaWarningCore());
 

misc/CMakeLists.txt

@@ -56,7 +56,7 @@ if (UNIX AND NOT APPLE)
   install(FILES ${TEXT_FILES} ${XCA_TEMPLATES}
         DESTINATION ${CMAKE_INSTALL_DATADIR}/${CMAKE_PROJECT_NAME}
   )
-  install(FILES misc/xca.desktop
+  install(FILES misc/de.hohnstaedt.xca.desktop
         DESTINATION ${CMAKE_INSTALL_DATADIR}/applications
   )
   install(FILES misc/xca.completion

misc/xca.desktop → misc/de.hohnstaedt.xca.desktop

@@ -1,5 +1,4 @@
 [Desktop Entry]
-Encoding=UTF-8
 Name=XCA
 Type=Application
 Comment=A graphical user interface for handling and issuing X.509 compliant Certificates
@@ -15,5 +14,5 @@ Comment[it]=Interfaccia grafica per generare e gestire certificati X.509
 Exec=xca %F
 Icon=de.hohnstaedt.xca
 Terminal=false
-Categories=Application;Utility;Qt;
+Categories=Utility;Qt
 MimeType=application/x-xca-database;application/x-xca-template;application/x-x509-ca-cert;application/pkcs10;application/x-pkcs7-certificates;application/x-pkcs12;