treewide: icons propagate hicolor-icon-theme, dontDropIconThemeCache

pkgs/data/icons/tango-icon-theme/default.nix

@@ -1,5 +1,5 @@
 { stdenv, fetchurl, intltool, pkgconfig, iconnamingutils, imagemagick, librsvg
-, gtk/*any version*/
+, gtk/*any version*/, hicolor-icon-theme
 }:
 
 stdenv.mkDerivation rec {
@@ -15,6 +15,12 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ intltool iconnamingutils imagemagick librsvg ];
 
+  propagatedBuildInputs = [
+    hicolor-icon-theme
+  ];
+
+  dontDropIconThemeCache = true;
+
   configureFlags = [ "--enable-png-creation" ];
 
   postInstall = '''${gtk.out}/bin/gtk-update-icon-cache' "$out/share/icons/Tango" '';