PY-19583 Fixed: Bad simplifying in condition

While inverting expression don't change operands order if original expression isn't comparison

python/src/com/jetbrains/python/inspections/quickfix/ChainedComparisonsQuickFix.java

@@ -145,14 +145,18 @@ public class ChainedComparisonsQuickFix implements LocalQuickFix {
 
   @NotNull
   private static PyExpression invertExpression(@NotNull PyBinaryExpression expression, @NotNull PyElementGenerator elementGenerator) {
-    final PsiElement operator = expression.getPsiOperator();
-    final PyExpression right = expression.getRightExpression();
-    PyExpression left = expression.getLeftExpression();
-    if (isComparisonExpression(left)) {
-      left = invertExpression((PyBinaryExpression)left, elementGenerator);
+    if (isComparisonExpression(expression)) {
+      final PyExpression left = expression.getLeftExpression();
+      final PyExpression right = expression.getRightExpression();
+
+      final String newOperator = invertOperator(assertNotNull(expression.getPsiOperator()));
+      final PyExpression newRight = isComparisonExpression(left) ? invertExpression((PyBinaryExpression)left, elementGenerator) : left;
+
+      return elementGenerator.createBinaryExpression(newOperator, right, newRight);
+    }
+    else {
+      return expression;
     }
-    final String newOperator = invertOperator(assertNotNull(operator));
-    return elementGenerator.createBinaryExpression(newOperator, right, left);
   }
 
   @NotNull

python/testData/inspections/ChainedComparison6.py

@@ -0,0 +1,4 @@
+class A:
+    def foo(self):
+        if index >= self.current and<caret> index - self.history_length < self.current:
+            pass

python/testData/inspections/ChainedComparison6_after.py

@@ -0,0 +1,4 @@
+class A:
+    def foo(self):
+        if index >= self.current > index - self.history_length:
+            pass

python/testSrc/com/jetbrains/python/PyQuickFixTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2013 JetBrains s.r.o.
+ * Copyright 2000-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -284,6 +284,11 @@ public class PyQuickFixTest extends PyTestCase {
     doInspectionTest(PyChainedComparisonsInspection.class, PyBundle.message("QFIX.chained.comparison"), true, true);
   }
 
+  // PY-19583
+  public void testChainedComparison6() {
+    doInspectionTest(PyChainedComparisonsInspection.class, "Simplify chained comparison", true, true);
+  }
+
   // PY-1362, PY-2585
   public void testStatementEffect() {
     doInspectionTest(PyStatementEffectInspection.class, PyBundle.message("QFIX.statement.effect"), true, true);