Fixed find usages for reassigned class and instance attributes (PY-4338).

python/src/com/jetbrains/python/psi/impl/PyQualifiedReferenceImpl.java

@@ -348,8 +348,8 @@ public class PyQualifiedReferenceImpl extends PyReferenceImpl {
         }
       }
     }
-    if (resolveResult instanceof PyTargetExpression && PyUtil.isInstanceAttribute((PyTargetExpression)resolveResult) &&
-        element instanceof PyTargetExpression && PyUtil.isInstanceAttribute((PyTargetExpression)element)) {
+    if (resolveResult instanceof PyTargetExpression && isInstanceOrClassAttribute((PyTargetExpression)resolveResult) &&
+        element instanceof PyTargetExpression && isInstanceOrClassAttribute((PyTargetExpression)element)) {
       PyClass aClass = PsiTreeUtil.getParentOfType(resolveResult, PyClass.class);
       PyClass bClass = PsiTreeUtil.getParentOfType(element, PyClass.class);
 
@@ -362,11 +362,15 @@ public class PyQualifiedReferenceImpl extends PyReferenceImpl {
     return false;
   }
 
-  private boolean isSubclass(@Nullable PyClass init, @Nullable PyClass usage) {
-    if (init == null || usage == null) {
+  private static boolean isInstanceOrClassAttribute(PyTargetExpression ex) {
+    return PyUtil.isInstanceAttribute(ex) || PyUtil.isClassAttribute(ex);
+  }
+
+  private static boolean isSubclass(@Nullable PyClass aClass, @Nullable PyClass bClass) {
+    if (aClass == null || bClass == null) {
       return false;
     }
-    return usage.isSubclass(init);
+    return bClass.isSubclass(aClass);
   }
 
   private static boolean isLocalScope(PsiElement element) {

python/testData/findUsages/ReassignedClassAttribute.py

@@ -0,0 +1,17 @@
+class A(object):
+    bacaba = 0
+    def __init__(self):
+        self.bacaba = 1
+
+    def foo(self, x):
+        self.bacaba = x
+
+
+class B(A):
+    bacaba = 2
+    def __init__(self):
+        super(B, self).__init__()
+        self.bacaba = 3
+
+    def foo2(self):
+        print self.bac<caret>aba

python/testData/findUsages/ReassignedInstanceAttribute.py

@@ -0,0 +1,18 @@
+class A(object):
+    def __init__(self):
+        self.bacaba = 1
+
+    def foo(self, x):
+        self.bacaba = x
+
+class B(A):
+    def __init__(self):
+        super(B, self).__init__()
+        self.bacaba = 2
+
+    def foo2(self):
+        self.ba<caret>caba = 3
+
+    def foo3(self):
+        print self.bacaba
+  

python/testSrc/com/jetbrains/python/PyFindUsagesTest.java

@@ -83,7 +83,7 @@ public class PyFindUsagesTest extends PyLightFixtureTestCase {
       }
     });
     for (int i = 0; i < usageTexts.length; i++) {
-      assertSameUsage(usageTexts [i], sortedUsages.get(i));
+      assertSameUsage(usageTexts[i], sortedUsages.get(i));
     }
   }
 
@@ -94,4 +94,14 @@ public class PyFindUsagesTest extends PyLightFixtureTestCase {
     final int startIndex = usageInfo.getElement().getTextOffset() + usageInfo.getRangeInElement().getStartOffset() - pos;
     assertEquals(usageText, myFixture.getFile().getText().substring(startIndex, startIndex + usageText.length()));
   }
+
+  public void testReassignedInstanceAttribute() {  // PY-4338
+    final Collection<UsageInfo> usages = myFixture.testFindUsages("findUsages/ReassignedInstanceAttribute.py");
+    assertEquals(5, usages.size());
+  }
+
+  public void testReassignedClassAttribute() {  // PY-4338
+    final Collection<UsageInfo> usages = myFixture.testFindUsages("findUsages/ReassignedClassAttribute.py");
+    assertEquals(5, usages.size());
+  }
 }