correctly resolve parameter names for tuples in parameter list (PY-882)

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

@@ -5,9 +5,10 @@ import com.intellij.psi.PsiElement;
 import com.jetbrains.python.PyElementTypes;
 import com.jetbrains.python.psi.*;
 import com.jetbrains.python.psi.stubs.PyParameterListStub;
-import com.jetbrains.python.toolbox.ArrayIterable;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.ArrayList;
+
 /**
  * @author yole
  */
@@ -140,7 +141,7 @@ public class PyParameterListImpl extends PyBaseElementImpl<PyParameterListStub>
 
   @NotNull
   public Iterable<PyElement> iterateNames() {
-    return new ArrayIterable<PyElement>(getParameters());
+    return new ArrayList<PyElement>(ParamHelper.collectNamedParameters(this));
   }
 
   public PyElement getElementNamed(final String the_name) {

python/testData/resolve/LambdaWithParens.py

@@ -0,0 +1 @@
+myidentityfunction = lambda(foo): f<ref>oo

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

@@ -240,6 +240,11 @@ public class PyResolveTest extends PyResolveTestCase {
     PsiElement targetElement = resolve();
     assertTrue(targetElement instanceof PyTargetExpression);
   }
+
+  public void testLambdaWithParens() {  // PY-882
+    PsiElement targetElement = resolve();
+    assertTrue(targetElement instanceof PyParameter);
+  }
   
   public void testTextBasedResolve() {
     ResolveResult[] resolveResults = multiResolve();