Fix 'recover' reference counting

Cython/Compiler/ExprNodes.py

@@ -11451,6 +11451,10 @@ class RecoverNode(ExprNode):
                 code.putln("#ifdef WITH_THREAD")
                 code.putln("PyGILState_Release(_save);")
                 code.putln("#endif")
+            if self.is_temp:
+                code.putln("%s = NULL;" % result_code)
+            if self.solid_operand.result_is_new_reference():
+                self.operand.generate_disposal_code(code)
             code.putln(
                 code.error_goto(self.pos))
             code.putln("}")

tests/run/cypclass_recover_refcount.pyx

@@ -61,6 +61,55 @@ def test_recover_and_drop_name():
 
     return 0
 
+cdef cypclass DoubleRefcounted(Refcounted):
+    DoubleRefcounted get_self(self):
+        return self
+
+
+def test_recover_and_drop_aliased_temporary():
+    """
+    >>> test_recover_and_drop_aliased_temporary()
+    'recover' operand is not isolated
+    Refcounted destroyed
+    0
+    """
+    r = DoubleRefcounted()
+    if Cy_GETREF(r) != 2:
+        return -1
+
+    try:
+        recover r.get_self()
+        return -2
+    except TypeError as e:
+        print(e)
+
+    if Cy_GETREF(r) != 2:
+        return -3
+
+    return 0
+
+def test_recover_and_drop_cast_aliased_temporary():
+    """
+    >>> test_recover_and_drop_cast_aliased_temporary()
+    'recover' operand is not isolated
+    Refcounted destroyed
+    0
+    """
+    r = DoubleRefcounted()
+    if Cy_GETREF(r) != 2:
+        return -1
+
+    try:
+        recover <DoubleRefcounted> r.get_self()
+        return -2
+    except TypeError as e:
+        print(e)
+
+    if Cy_GETREF(r) != 2:
+        return -3
+
+    return 0
+
 def test_recover_constructed():
     """
     >>> test_recover_constructed()