asciidoc: support extra filters (ditaa, mscgen, diag)

Also, slightly change the shebang fixup in the patchPhase so that it
handles optional [[:space:]] before the interpreter path (needed for the
filters).

To enable the extra filters, put this in packageOverrides:

  asciidoc = pkgs.asciidoc.override {
    enableDitaaFilter = true;
    enableMscgenFilter = true;
    enableDiagFilter = true;
  };

pkgs/tools/typesetting/asciidoc/default.nix

@@ -1,15 +1,70 @@
-{ fetchurl, stdenv, python }:
+{ fetchurl, stdenv, python
+, unzip ? null
+, enableDitaaFilter ? false, jre ? null
+, enableMscgenFilter ? false, mscgen ? null
+, enableDiagFilter ? false, blockdiag ? null, seqdiag ? null, actdiag ? null, nwdiag ? null
+}:
+
+assert (enableDitaaFilter || enableMscgenFilter || enableDiagFilter) -> unzip != null;
+assert enableDitaaFilter -> jre != null;
+assert enableMscgenFilter -> mscgen != null;
+assert enableDiagFilter -> blockdiag != null && seqdiag != null && actdiag != null && nwdiag != null;
+
+let
+  ditaaFilterSrc = fetchurl {
+    url = "https://asciidoc-ditaa-filter.googlecode.com/files/ditaa-filter-1.1.zip";
+    sha256 = "0p7hm2a1xywx982ia3vg4c0lam5sz0xknsc10i2a5vswy026naf6";
+  };
+
+  mscgenFilterSrc = fetchurl {
+    url = "https://asciidoc-mscgen-filter.googlecode.com/files/mscgen-filter-1.2.zip";
+    sha256 = "1nfwmj375gpv5dn9i770pjv59aihzy2kja0fflsk96xwnlqsqq61";
+  };
+
+  diagFilterSrc = fetchurl {
+    # unfortunately no version number
+    url = "https://asciidoc-diag-filter.googlecode.com/files/diag_filter.zip";
+    sha256 = "1qlqrdbqkdqqgfdhjsgdws1al0sacsyq6jmwxdfy7r8k7bv7n7mm";
+  };
+
+in
 
 stdenv.mkDerivation rec {
   name = "asciidoc-8.6.8";
+
   src = fetchurl {
     url = "mirror://sourceforge/asciidoc/${name}.tar.gz";
     sha256 = "ffb67f59dccaf6f15db72fcd04fdf21a2f9b703d31f94fcd0c49a424a9fcfbc4";
   };
 
-  patchPhase = ''
+  buildInputs = [ python unzip ];
-    for n in `find . -name \*.py `; do
+
-      sed -i -e "s,^#!/usr/bin/env python,#!${python}/bin/python,g" "$n"
+  # install filters early, so their shebangs are patched too
+  patchPhase = with stdenv.lib; ''
+    mkdir -p "$out/etc/asciidoc/filters"
+  '' + optionalString enableDitaaFilter ''
+    echo "Extracting ditaa filter"
+    unzip -d "$out/etc/asciidoc/filters/ditaa" "${ditaaFilterSrc}"
+    sed -i -e "s|java -jar|${jre}/bin/java -jar|" \
+        "$out/etc/asciidoc/filters/ditaa/ditaa2img.py"
+  '' + optionalString enableMscgenFilter ''
+    echo "Extracting mscgen filter"
+    unzip -d "$out/etc/asciidoc/filters/mscgen" "${mscgenFilterSrc}"
+    sed -i -e "s|filter-wrapper.py mscgen|filter-wrapper.py ${mscgen}/bin/mscgen|" \
+        "$out/etc/asciidoc/filters/mscgen/mscgen-filter.conf"
+  '' + optionalString enableDiagFilter ''
+    echo "Extracting diag filter"
+    unzip -d "$out/etc/asciidoc/filters/diag" "${diagFilterSrc}"
+    sed -i \
+        -e "s|filter='blockdiag|filter=\'${blockdiag}/bin/blockdiag|" \
+        -e "s|filter='seqdiag|filter=\'${seqdiag}/bin/seqdiag|" \
+        -e "s|filter='actdiag|filter=\'${actdiag}/bin/actdiag|" \
+        -e "s|filter='nwdiag|filter=\'${nwdiag}/bin/nwdiag|" \
+        -e "s|filter='packetdiag|filter=\'${nwdiag}/bin/packetdiag|" \
+        "$out/etc/asciidoc/filters/diag/diag-filter.conf"
+  '' + ''
+    for n in $(find "$out" . -name \*.py); do
+      sed -i -e "s,^#![[:space:]]*/usr/bin/env python,#!${python}/bin/python,g" "$n"
       chmod +x "$n"
     done
     sed -i -e "s,/etc/vim,,g" Makefile.in
@@ -17,8 +72,6 @@ stdenv.mkDerivation rec {
 
   preInstall = "mkdir -p $out/etc/vim";
 
-  buildInputs = [ python ];
-
   meta = {
     homepage = "http://www.methods.co.nz/asciidoc/";
     description = "ASCII text-based document generation system";