fix one more case for IDEA-86027 and fix test

plugins/IntentionPowerPak/src/com/siyeh/ipp/opassign/ReplaceOperatorAssignmentWithAssignmentIntention.java

@@ -81,7 +81,7 @@ public class ReplaceOperatorAssignmentWithAssignmentIntention
       final IElementType signTokenType = sign.getTokenType();
       final IElementType newOperatorToken = tokenMap.get(signTokenType);
       final int precedence2 = ParenthesesUtils.getPrecedenceForBinaryOperator(newOperatorToken);
-      parentheses = precedence1 > precedence2 || !ParenthesesUtils.isCommutativeBinaryOperator(newOperatorToken);
+      parentheses = precedence1 >= precedence2 || !ParenthesesUtils.isCommutativeBinaryOperator(newOperatorToken);
     }
     else {
       parentheses = false;

plugins/IntentionPowerPak/test/com/siyeh/ipp/opassign/assignment/ByteOpassign_after.java

@@ -3,6 +3,6 @@ package com.siyeh.ipp.opassign.assignment;
 class ByteOpassign {
 
   void foo(byte b) {
-      b = (byte)(b + 1);
+      b = (byte) (b + 1);
   }
 }

plugins/IntentionPowerPak/test/com/siyeh/ipp/opassign/assignment/Precedence.java

@@ -0,0 +1,10 @@
+package com.siyeh.ipp.opassign.assignment;
+
+class Precedence {
+
+  void foo() {
+      int a = Integer.MAX_VALUE;
+      double d = Double.MAX_VALUE;
+      a<caret> += d - d;// a == 2147483647;
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/opassign/assignment/Precedence_after.java

@@ -0,0 +1,10 @@
+package com.siyeh.ipp.opassign.assignment;
+
+class Precedence {
+
+  void foo() {
+      int a = Integer.MAX_VALUE;
+      double d = Double.MAX_VALUE;
+      a = (int) (a + (d - d));// a == 2147483647;
+  }
+}

plugins/IntentionPowerPak/testSrc/com/siyeh/ipp/opassign/ReplaceOperatorAssignmentWithAssignmentIntentionTest.java

@@ -5,9 +5,10 @@ import com.siyeh.ipp.IPPTestCase;
 
 public class ReplaceOperatorAssignmentWithAssignmentIntentionTest extends IPPTestCase {
   public void testOperatorAssignment1() { doTest(); }
-  public void DoubleOpAssign() { doTest(); }
-  public void StringOpAssign() { doTest(); }
-  public void ByteOpAssign() { doTest(); }
+  public void testDoubleOpAssign() { doTest(); }
+  public void testStringOpAssign() { doTest(); }
+  public void testByteOpAssign() { doTest(); }
+  public void testPrecedence() { doTest(); }
 
   @Override
   protected String getIntentionName() {