espeak-ng: add mbrola support

pkgs/applications/audio/espeak-ng/default.nix

@@ -1,5 +1,6 @@
 { stdenv, lib, fetchFromGitHub, autoconf, automake, which, libtool, pkg-config
-, ronn
+, ronn, substituteAll
+, mbrolaSupport ? true, mbrola
 , pcaudiolibSupport ? true, pcaudiolib
 , sonicSupport ? true, sonic }:
 
@@ -14,13 +15,26 @@ stdenv.mkDerivation rec {
     sha256 = "0jkqhf2h94vbqq7mg7mmm23bq372fa7mdk941my18c3vkldcir1b";
   };
 
+  patches = lib.optionals mbrolaSupport [
+    # Hardcode correct mbrola paths.
+    (substituteAll {
+      src = ./mbrola.patch;
+      inherit mbrola;
+    })
+  ];
+
   nativeBuildInputs = [ autoconf automake which libtool pkg-config ronn ];
 
-  buildInputs = lib.optional pcaudiolibSupport pcaudiolib
+  buildInputs = lib.optional mbrolaSupport mbrola
+             ++ lib.optional pcaudiolibSupport pcaudiolib
              ++ lib.optional sonicSupport sonic;
 
   preConfigure = "./autogen.sh";
 
+  configureFlags = [
+    "--with-mbrola=${if mbrolaSupport then "yes" else "no"}"
+  ];
+
   postInstall = lib.optionalString stdenv.isLinux ''
     patchelf --set-rpath "$(patchelf --print-rpath $out/bin/espeak-ng)" $out/bin/speak-ng
   '';
@@ -29,7 +43,7 @@ stdenv.mkDerivation rec {
     description = "Open source speech synthesizer that supports over 70 languages, based on eSpeak";
     homepage = "https://github.com/espeak-ng/espeak-ng";
     changelog = "https://github.com/espeak-ng/espeak-ng/blob/${version}/CHANGELOG.md";
-    license = licenses.gpl3;
+    license = licenses.gpl3Plus;
     maintainers = with maintainers; [ aske ];
     platforms = platforms.all;
   };