libxml2: fix CVE-2020-24977

Fixes an out-of-bounds read when using xmllint with the --htmlout
parameter.

Fixes: CVE-2020-24977

pkgs/development/libraries/libxml2/default.nix

@@ -27,15 +27,20 @@ stdenv.mkDerivation rec {
     #   https://github.com/NixOS/nixpkgs/pull/63174
     #   https://github.com/NixOS/nixpkgs/pull/72342
     ./utf8-xmlErrorFuncHandler.patch
+    (fetchpatch {
+      name = "CVE-2019-20388.patch";
+      url = "https://gitlab.gnome.org/GNOME/libxml2/commit/6088a74bcf7d0c42e24cff4594d804e1d3c9fbca.patch";
+      sha256 = "070s7al2r2k92320h9cdfc2097jy4kk04d0disc98ddc165r80jl";
+    })
     (fetchpatch {
       name = "CVE-2020-7595.patch";
       url = "https://gitlab.gnome.org/GNOME/libxml2/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5.patch";
       sha256 = "0klvaxkzakkpyq0m44l9xrpn5kwaii194sqsivfm6zhnb9hhl15l";
     })
     (fetchpatch {
-      name = "CVE-2019-20388.patch";
-      url = "https://gitlab.gnome.org/GNOME/libxml2/commit/6088a74bcf7d0c42e24cff4594d804e1d3c9fbca.patch";
-      sha256 = "070s7al2r2k92320h9cdfc2097jy4kk04d0disc98ddc165r80jl";
+      name = "CVE-2020-24977.patch";
+      url = "https://gitlab.gnome.org/GNOME/libxml2/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2.patch";
+      sha256 = "093f1ic5qfiq8nk9mc6b8p1qcs8m9hir3ardr6r5il4zi2dnjrj4";
     })
   ];