xmlsec: add library path to lt_dladdsearchdir

This makes it easier to use libxmlsec in other libraries like
python-xmlsec.

pkgs/development/libraries/xmlsec/default.nix

@@ -1,5 +1,5 @@
 { stdenv, fetchurl, libxml2, gnutls, libxslt, pkgconfig, libgcrypt, libtool
-, openssl, nss, makeWrapper }:
+, openssl, nss }:
 
 let
   version = "1.2.28";
@@ -13,9 +13,16 @@ stdenv.mkDerivation {
     sha256 = "1m12caglhyx08g8lh2sl3nkldlpryzdx2d572q73y3m33s0w9vhk";
   };
 
+  patches = [
+    ./lt_dladdsearchdir.patch
+  ];
+  postPatch = ''
+    substituteAllInPlace src/dl.c
+  '';
+
   outputs = [ "out" "dev" ];
 
-  nativeBuildInputs = [ makeWrapper pkgconfig ];
+  nativeBuildInputs = [ pkgconfig ];
 
   buildInputs = [ libxml2 gnutls libxslt libgcrypt libtool openssl nss ];
 
@@ -34,10 +41,6 @@ stdenv.mkDerivation {
     moveToOutput "lib/xmlsec1Conf.sh" "$dev"
   '';
 
-  postFixup = ''
-    wrapProgram "$out/bin/xmlsec1" --prefix LD_LIBRARY_PATH ":" "$out/lib"
-  '';
-
   meta = {
     homepage = http://www.aleksey.com/xmlsec;
     downloadPage = https://www.aleksey.com/xmlsec/download.html;

pkgs/development/libraries/xmlsec/lt_dladdsearchdir.patch

@@ -0,0 +1,16 @@
+diff --git a/src/dl.c b/src/dl.c
+index b13f9d46..d761855b 100644
+--- a/src/dl.c
++++ b/src/dl.c
+@@ -346,6 +346,11 @@ xmlSecCryptoDLInit(void) {
+         xmlSecIOError("lt_dlinit", NULL, NULL);
+         return(-1);
+     }
++    ret = lt_dladdsearchdir("@out@/lib");
++    if(ret != 0) {
++      xmlSecIOError("lt_dladdsearchdir", NULL, NULL);
++      return(-1);
++    }
+ #endif /* XMLSEC_DL_LIBLTDL */
+ 
+     return(0);