Adding a manpage for tar, using help2man

svn path=/nixpkgs/trunk/; revision=32749

pkgs/tools/archivers/gnutar/default.nix

@@ -1,6 +1,8 @@
-{stdenv, fetchurl}:
+{stdenv, fetchurl, withMan ? false, help2man ? null}:
 
-stdenv.mkDerivation rec {
+assert withMan -> help2man != null;
+
+stdenv.mkDerivation (rec {
   name = "gnutar-1.25";
 
   src = fetchurl {
@@ -32,4 +34,10 @@ stdenv.mkDerivation rec {
     maintainers = [ stdenv.lib.maintainers.ludo ];
     platforms = stdenv.lib.platforms.all;
   };
-}
+} // (if withMan then {
+  buildInputs = [ help2man ];
+  postInstall = ''
+    ensureDir $out/share/man/man1
+    help2man $out/bin/tar > $out/share/man/man1/tar.1
+  '';
+} else {}))