no arg set.__init__() should clear data

Author: tomasstupka

graalpython/com.oracle.graal.python.test/src/tests/test_set.py

@@ -40,6 +40,7 @@
 # ankitv 10/10/13
 # Iterating by Sequence Index
 
+from collections.abc import MutableSet
 
 def assert_raises(err, fn, *args, **kwargs):
     raised = False
@@ -315,6 +316,12 @@ def test_same_id():
     empty_ids = set([id(frozenset()) for i in range(100)])
     assert len(empty_ids) == 1
 
+def test_init():
+    s = {1, 2, 3}
+    s.__init__({4})
+    assert s == {4}
+    s.__init__()
+    assert s == set()
 
 def test_rich_compare():
     class TestRichSetCompare:

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/set/SetBuiltins.java

@@ -86,9 +86,11 @@ protected List<? extends NodeFactory<? extends PythonBuiltinBaseNode>> getNodeFa
     @ImportStatic(PGuards.class)
     public abstract static class InitNode extends PythonBuiltinNode {
 
-        @Specialization(guards = "isNoValue(iterable)")
-        @SuppressWarnings("unused")
-        static PNone doNoValue(VirtualFrame frame, PSet self, PNone iterable) {
+        @Specialization(guards = "isNoValue(iterable)", limit = "1")
+        static PNone doNoValue(PSet self, @SuppressWarnings("unused") PNone iterable,
+                        @CachedLibrary("self.getDictStorage()") HashingStorageLibrary lib) {
+            HashingStorage newStorage = lib.clear(self.getDictStorage());
+            self.setDictStorage(newStorage);
             return PNone.NONE;
         }