fix incorrect resolve to self in tuple expressions; fix possible SOE

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

@@ -240,6 +240,9 @@ public class PyReferenceExpressionImpl extends PyElementImpl implements PyRefere
       }
     }
     PsiElement target = resolve();
+    if (target == this) {
+      return null;
+    }
     return getTypeFromTarget(target);
   }
 

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

@@ -54,7 +54,7 @@ public class PyTupleExpressionImpl extends PyElementImpl implements PyTupleExpre
                                      PsiElement lastParent,
                                      @NotNull PsiElement place) {
     for (PyExpression expression : getElements()) {
-      if (!expression.processDeclarations(processor, substitutor, lastParent, place)) {
+      if (expression != lastParent && !expression.processDeclarations(processor, substitutor, lastParent, place)) {
         return false;
       }
     }

python/testData/resolve/Tuple.py

@@ -0,0 +1,3 @@
+aa = 1
+bb = 2
+c = aa, b<ref>b

python/testSrc/com/jetbrains/python/PyResolveTest.java

@@ -87,6 +87,12 @@ public class PyResolveTest extends ResolveTestCase {
     assertTrue(targetElement instanceof PyTargetExpression);
   }
 
+  public void testTuple() throws Exception {
+    PsiElement targetElement = resolve();
+    assertTrue(targetElement instanceof PyTargetExpression);
+    assertTrue(targetElement.getParent() instanceof PyAssignmentStatement);
+  }
+
   @Override
   protected String getTestDataPath() {
     return PathManager.getHomePath() + "/plugins/python/testData/resolve/";