IDEA-110917 Incorrect "Redundant Cast" on Complex Conditional

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

@@ -390,6 +390,10 @@ public class RedundantCastUtil {
               return;
             }
             if (!checkResolveAfterRemoveCast(parent)) return;
+            final PsiExpression thenExpression = ((PsiConditionalExpression)parent).getThenExpression();
+            final PsiExpression elseExpression = ((PsiConditionalExpression)parent).getElseExpression();
+            final PsiExpression opposite = thenExpression == typeCast ? elseExpression : thenExpression;
+            if (opposite == null || !Comparing.equal(conditionalType, opposite.getType())) return;
           }
         } else if (parent instanceof PsiSynchronizedStatement && (expr instanceof PsiExpression && ((PsiExpression)expr).getType() instanceof PsiPrimitiveType)) {
           return;

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting6/RedundantCastInConditionalExpression.java

@@ -0,0 +1,8 @@
+public class Foo {
+    public static void main(String[] args) {
+        final boolean b = false;
+        final Integer i = (<warning descr="Casting '3' to 'Integer' is redundant">Integer</warning>)3;
+        final short s = (short)(b ? i : (int)Integer.valueOf(3));
+        System.out.println(s);
+    }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk6Test.java

@@ -57,4 +57,5 @@ public class LightAdvHighlightingJdk6Test extends LightDaemonAnalyzerTestCase {
   public void testIDEADEV11877() throws Exception { setLanguageLevel(LanguageLevel.JDK_1_6); doTest(false, false); }
   public void testIDEA108285() throws Exception { setLanguageLevel(LanguageLevel.JDK_1_6); doTest(false, false); }
   public void testClassObjectAccessibility() throws Exception { setLanguageLevel(LanguageLevel.JDK_1_6); doTest(false, false); }
+  public void testRedundantCastInConditionalExpression() throws Exception { setLanguageLevel(LanguageLevel.JDK_1_6); doTest(true, false); }
 }