redundant cast: always report casts in instanceOf checks for class types; exclude primitive types

java/java-psi-api/src/com/intellij/psi/util/RedundantCastUtil.java

@@ -21,7 +21,6 @@ import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Ref;
 import com.intellij.psi.*;
 import com.intellij.psi.codeStyle.CodeStyleManager;
-import com.intellij.psi.impl.source.resolve.DefaultParameterTypeInferencePolicy;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.util.ArrayUtil;
 import com.intellij.util.IncorrectOperationException;
@@ -494,7 +493,10 @@ public class RedundantCastUtil {
         }
       }
       else {
-        if (TypeConversionUtil.isAssignable(castTo, opType, false)) {
+        if (parent instanceof PsiInstanceOfExpression && opType instanceof PsiPrimitiveType) {
+          return;
+        }
+        if (parent instanceof PsiInstanceOfExpression || TypeConversionUtil.isAssignable(castTo, opType, false)) {
           addToResults(typeCast);
         }
       }

java/java-tests/testData/inspection/redundantCast/generics/InstanceOfChecks/expected.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems>
+  <problem>
+    <file>Test.java</file>
+    <line>8</line>
+    <description>Casting &lt;code&gt;o&lt;/code&gt; to &lt;code&gt;List&lt;/code&gt; is redundant</description>
+  </problem>
+</problems>

java/java-tests/testData/inspection/redundantCast/generics/InstanceOfChecks/src/Test.java

@@ -0,0 +1,10 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class RedundantCast {
+    boolean redundantCasts(Object o) {
+        int p = 0;
+        if ((Number)p instanceof Integer) {}
+        return (List)o instanceof ArrayList;
+    }
+}

java/java-tests/testSrc/com/intellij/codeInspection/RedundantCast15Test.java

@@ -47,6 +47,7 @@ public class RedundantCast15Test extends InspectionTestCase {
   public void testRawCast1() throws Exception { doTest();}
   public void testInferenceFromCast() throws Exception { doTest();}
   public void testGetClassProcessing() throws Exception { doTest();}
+  public void testInstanceOfChecks() throws Exception { doTest();}
 
   public void testTypeParameterAccessChecksJava7() throws Exception {
     IdeaTestUtil.setTestVersion(JavaSdkVersion.JDK_1_7, getModule(), getTestRootDisposable());