Add 'third_party/nix/' from commit 'be66c7a6b24e3c3c6157fd37b86c7203d14acf10'

git-subtree-dir: third_party/nix
git-subtree-mainline: cf8cd640c1
git-subtree-split: be66c7a6b24e3c3c6157fd37b86c7203d14acf10

third_party/nix/tests/plugins/plugintest.cc

@@ -0,0 +1,24 @@
+#include "config.hh"
+#include "primops.hh"
+
+using namespace nix;
+
+struct MySettings : Config
+{
+    Setting<bool> settingSet{this, false, "setting-set",
+        "Whether the plugin-defined setting was set"};
+};
+
+MySettings mySettings;
+
+static GlobalConfig::Register rs(&mySettings);
+
+static void prim_anotherNull (EvalState & state, const Pos & pos, Value ** args, Value & v)
+{
+    if (mySettings.settingSet)
+        mkNull(v);
+    else
+        mkBool(v, false);
+}
+
+static RegisterPrimOp rp("anotherNull", 0, prim_anotherNull);