fixed PY-10420 False positive in redundant parentheses inspection with yield

python/src/com/jetbrains/python/inspections/PyRedundantParenthesesInspection.java

@@ -57,7 +57,7 @@ public class PyRedundantParenthesesInspection extends PyInspection {
       PyExpression expression = node.getContainedExpression();
       if (node.getText().contains("\n")) return;
       PyYieldExpression yieldExpression = PsiTreeUtil.getParentOfType(expression, PyYieldExpression.class, false);
-      if (yieldExpression != null && yieldExpression.isDelegating()) return;
+      if (yieldExpression != null) return;
       if (expression instanceof PyReferenceExpression || expression instanceof PyLiteralExpression) {
         if (myIgnorePercOperator) {
           PsiElement parent = node.getParent();

python/testData/inspections/PyRedundantParenthesesInspection/Yield.py

@@ -0,0 +1,3 @@
+def foo():
+  if (yield 1):
+    pass

python/testSrc/com/jetbrains/python/inspections/PyRedundantParenthesesInspectionTest.java

@@ -60,4 +60,8 @@ public class PyRedundantParenthesesInspectionTest extends PyTestCase {
     doTest(LanguageLevel.PYTHON33);
   }
 
+  public void testYield() {       //PY-10420
+    doTest(LanguageLevel.PYTHON27);
+  }
+
 }