From 69688bf2caa7b612aa196982595cae25d439ffea Mon Sep 17 00:00:00 2001
From: Dmitry Jemerov <yole@jetbrains.com>
Date: Thu, 26 Apr 2012 09:40:00 +0200
Subject: [PATCH] correct semantics of __slots__ with inheritance (PY-5939)

---
 .../PyUnresolvedReferencesInspection.java      | 18 ++++++++++++++++--
 .../slotsSubclass.py                           | 15 +++++++++++++++
 .../PyUnresolvedReferencesInspectionTest.java  |  4 ++++
 3 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 python/testData/inspections/PyUnresolvedReferencesInspection/slotsSubclass.py

diff --git a/python/src/com/jetbrains/python/inspections/PyUnresolvedReferencesInspection.java b/python/src/com/jetbrains/python/inspections/PyUnresolvedReferencesInspection.java
index 53b14f82241d..676dba6b0d17 100644
--- a/python/src/com/jetbrains/python/inspections/PyUnresolvedReferencesInspection.java
+++ b/python/src/com/jetbrains/python/inspections/PyUnresolvedReferencesInspection.java
@@ -154,10 +154,24 @@ public class PyUnresolvedReferencesInspection extends PyInspection {
           final PyClass pyClass = ((PyClassType)type).getPyClass();
           if (pyClass != null && pyClass.isNewStyleClass()) {
             final List<String> slots = pyClass.getSlots();
-            if (slots != null && !slots.contains(node.getReferencedName()) && !slots.contains("__dict__")) {
+            final String attrName = node.getReferencedName();
+            if (slots != null && !slots.contains(attrName) && !slots.contains(PyNames.DICT)) {
+              for (PyClassRef ref : pyClass.iterateAncestors()) {
+                final PyClass ancestor = ref.getPyClass();
+                if (ancestor == null) {
+                  return;
+                }
+                if (PyNames.OBJECT.equals(ancestor.getName())) {
+                  break;
+                }
+                final List<String> ancestorSlots = ancestor.getSlots();
+                if (ancestorSlots == null || ancestorSlots.contains(attrName) || ancestorSlots.contains(PyNames.DICT)) {
+                  return;
+                }
+              }
               final ASTNode nameNode = node.getNameElement();
               final PsiElement e = nameNode != null ? nameNode.getPsi() : node;
-              registerProblem(e, "'" + pyClass.getName() + "' object has no attribute '" + node.getReferencedName() + "'");
+              registerProblem(e, "'" + pyClass.getName() + "' object has no attribute '" + attrName + "'");
             }
           }
         }
diff --git a/python/testData/inspections/PyUnresolvedReferencesInspection/slotsSubclass.py b/python/testData/inspections/PyUnresolvedReferencesInspection/slotsSubclass.py
new file mode 100644
index 000000000000..dfd3f5e4cc50
--- /dev/null
+++ b/python/testData/inspections/PyUnresolvedReferencesInspection/slotsSubclass.py
@@ -0,0 +1,15 @@
+class A(object):
+    __slots__ = ['a', 'b']
+    def __init__(self):
+        self.a = None # <- all ok here
+        self.b = None # <- all ok here
+
+class C(A):
+    __slots__ = ['c', 'd']
+
+    def __init__(self, c):
+        super(C, self).__init__()
+        self.c = c
+        self.d = self.b
+        if self.c:
+            self.a = 10
diff --git a/python/testSrc/com/jetbrains/python/inspections/PyUnresolvedReferencesInspectionTest.java b/python/testSrc/com/jetbrains/python/inspections/PyUnresolvedReferencesInspectionTest.java
index d9b498db8d5b..b74ba65d5de4 100644
--- a/python/testSrc/com/jetbrains/python/inspections/PyUnresolvedReferencesInspectionTest.java
+++ b/python/testSrc/com/jetbrains/python/inspections/PyUnresolvedReferencesInspectionTest.java
@@ -32,6 +32,10 @@ public class PyUnresolvedReferencesInspectionTest extends PyTestCase {
     doTest();
   }
 
+  public void testSlotsSubclass() {  // PY-5939
+    doTest();
+  }
+
   public void testImportExceptImportError() {
     doTest();
   }