schema: adds ability to get when context nodes

This patch adds ability to get context schema node from which when
contition is evaluated. It also fixes memory leak of original
when_conditions

Signed-off-by: Stefan Gula <steweg@gmail.com>

Author: steweg

libyang/schema.py

@@ -1440,13 +1440,23 @@ def parent(self) -> Optional["SNode"]:
         return None
 
     def when_conditions(self):
-        wh = ffi.new("struct lysc_when **")
         wh = lib.lysc_node_when(self.cdata)
         if wh == ffi.NULL:
             return
         for cond in ly_array_iter(wh):
             yield c2str(lib.lyxp_get_expr(cond.cond))
 
+    def when_conditions_nodes(self) -> Iterator[Optional["SNode"]]:
+        wh = lib.lysc_node_when(self.cdata)
+        if wh == ffi.NULL:
+            return
+        for cond in ly_array_iter(wh):
+            yield (
+                None
+                if cond.context == ffi.NULL
+                else SNode.new(self.context, cond.context)
+            )
+
     def parsed(self) -> Optional["PNode"]:
         if self.cdata_parsed is None or self.cdata_parsed == ffi.NULL:
             return None

tests/test_schema.py

@@ -918,6 +918,14 @@ def tearDown(self):
         self.ctx.destroy()
         self.ctx = None
 
+    def test_anydata(self):
+        snode = next(self.ctx.find_path("/yolo-nodetypes:any1"))
+        self.assertIsInstance(snode, SAnydata)
+        assert next(snode.when_conditions()) is not None
+        snode2 = next(snode.when_conditions_nodes())
+        assert isinstance(snode2, SAnydata)
+        assert snode2.cdata == snode.cdata
+
     def test_anydata_parsed(self):
         snode = next(self.ctx.find_path("/yolo-nodetypes:any1"))
         self.assertIsInstance(snode, SAnydata)