sed: bring back 4.2.2 temporarily

It will be useful to fixup compatibility problems with [:space:].

pkgs/tools/text/gnused/422.nix

@@ -0,0 +1,31 @@
+{ stdenv, fetchurl }:
+
+stdenv.mkDerivation {
+  name = "gnused-4.2.2";
+
+  src = fetchurl {
+    url = mirror://gnu/sed/sed-4.2.2.tar.bz2;
+    sha256 = "f048d1838da284c8bc9753e4506b85a1e0cc1ea8999d36f6995bcb9460cddbd7";
+  };
+
+  outputs = [ "out" "info" ];
+
+  meta = {
+    homepage = http://www.gnu.org/software/sed/;
+    description = "GNU sed, a batch stream editor";
+
+    longDescription = ''
+      Sed (stream editor) isn't really a true text editor or text
+      processor.  Instead, it is used to filter text, i.e., it takes
+      text input and performs some operation (or set of operations) on
+      it and outputs the modified text.  Sed is typically used for
+      extracting part of a file using pattern matching or substituting
+      multiple occurrences of a string within a file.
+    '';
+
+    license = stdenv.lib.licenses.gpl3Plus;
+
+    platforms = stdenv.lib.platforms.all;
+    maintainers = [ ];
+  };
+}

pkgs/top-level/all-packages.nix

@@ -1940,6 +1940,8 @@ in
   gnuplot_aquaterm = gnuplot.override { aquaterm = true; };
 
   gnused = callPackage ../tools/text/gnused { };
+  # This is an easy work-around for [:space:] problems.
+  gnused_422 = callPackage ../tools/text/gnused/422.nix { };
 
   gnutar = callPackage ../tools/archivers/gnutar { };