librdf_raptor2: backport fix for `libxml2-2.11`

`libxml2-2.11` removed `checked` bit of private API and broke
`librdf_raptor2` build as:

       src/raptor_libxml.c:256:12: error: 'xmlEntity' {aka 'struct _xmlEntity'} has no member named 'checked'
         256 |     if(!ret->checked)
             |            ^~

The change pull upstream fix.

1 files changed, 7 insertions, 0 deletions

diff --git a/pkgs/development/libraries/librdf/raptor2.nix b/pkgs/development/libraries/librdf/raptor2.nix
index b085e080803..4503a0cc43e 100644
--- a/pkgs/development/libraries/librdf/raptor2.nix
+++ b/pkgs/development/libraries/librdf/raptor2.nix
@@ -35,6 +35,13 @@ stdenv.mkDerivation rec {
       url = "https://github.com/dajobe/raptor/commit/fa1ef9a27d8762f5588ac2e92554a188e73dee9f.diff";
       sha256 = "sha256-zXIbrYGgC9oTpiD0WUikT4vRdc9b6bsyfnDkwUSlqao=";
     })
+    # pull upstream fix for libxml2-2.11 API compatibility:
+    #   https://github.com/dajobe/raptor/pull/58
+    (fetchpatch {
+      name = "libxml2-2.11.patch";
+      url = "https://github.com/dajobe/raptor/commit/4dbc4c1da2a033c497d84a1291c46f416a9cac51.patch";
+      hash = "sha256-fHfvncGymzMtxjwtakCNSr/Lem12UPIHAAcAac648w4=";
+    })
   ];
 
   nativeBuildInputs = [ pkg-config cmake perl bison flex ];