libyaml: update from 0.1.7 to version 0.2.1

This update includes two hitherto unreleased upstream patches to fix bugs in
0.2.1 that manifest in the pythonPackages.pyyaml test suite.

Closes #45560.

pkgs/development/libraries/libyaml/default.nix

@@ -1,16 +1,31 @@
-{ stdenv, fetchurl }:
+{ stdenv, fetchurl, fetchpatch }:
+
 let
-  # 0.2.1 broke the tests of pythonPackages.pyyaml 3.13
-  version = "0.1.7";
+
+  version = "0.2.1";
+
+  # https://github.com/yaml/pyyaml/issues/214
+  p1 = fetchpatch {
+         url = https://github.com/yaml/libyaml/commit/8ee83c0da22fe9aa7dea667be8f899a7e32ffb83.patch;
+         sha256 = "00jh39zww6s4gyhxfmlxwb6lz90nl3p51k5h1qm6z3ymik5vljmz";
+       };
+  p2 = fetchpatch {
+         url = https://github.com/yaml/libyaml/commit/56f4b17221868593d6903ee58d6d679b690cf4df.patch;
+         sha256 = "0najcay1y4kgfpsidj7dnyafnwjbav5jyawhyv215zl9gg3386n0";
+       };
+
 in
+
 stdenv.mkDerivation {
   name = "libyaml-${version}";
 
   src = fetchurl {
     url = "https://pyyaml.org/download/libyaml/yaml-${version}.tar.gz";
-    sha256 = "0a87931cx5m14a1x8rbjix3nz7agrcgndf4h392vm62a4rby9240";
+    sha256 = "1karpcfgacgppa82wm2drcfn2kb6q2wqfykf5nrhy20sci2i2a3q";
   };
 
+  patches = [ p1 p2 ];  # remove when the next release comes out
+
   meta = with stdenv.lib; {
     homepage = https://pyyaml.org/;
     description = "A YAML 1.1 parser and emitter written in C";