extract method: exclude return statements without value from occurrence analyzing; do not suggest artificial return type if return statements break control flow

java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java

@@ -344,7 +344,7 @@ public class ExtractMethodProcessor implements MatchProvider {
 
   @Nullable
   private PsiVariable getArtificialOutputVariable() {
-    if (myOutputVariables.length == 0) {
+    if (myOutputVariables.length == 0 && myExitStatements.isEmpty()) {
       if (myCanBeChainedConstructor) {
         final Set<PsiField> fields = new HashSet<PsiField>();
         for (PsiElement element : myElements) {
@@ -616,7 +616,7 @@ public class ExtractMethodProcessor implements MatchProvider {
     final List<PsiStatement> filter = ContainerUtil.filter(myExitStatements, new Condition<PsiStatement>() {
       @Override
       public boolean value(PsiStatement statement) {
-        return statement instanceof PsiReturnStatement;
+        return statement instanceof PsiReturnStatement && ((PsiReturnStatement)statement).getReturnValue() != null;
       }
     });
     final List<PsiExpression> map = ContainerUtil.map(filter, new Function<PsiStatement, PsiExpression>() {

java/java-tests/testData/refactoring/extractMethod/NoReturnTypesSuggested.java

@@ -0,0 +1,7 @@
+class X {
+  void foo() {
+      <selection>if (true) return;
+      System.out.println();
+      </selection>
+  }
+}

java/java-tests/testData/refactoring/extractMethod/NoReturnTypesSuggested_after.java

@@ -0,0 +1,11 @@
+class X {
+  void foo() {
+      newMethod();
+      
+  }
+
+    private int newMethod() {
+        if (true) return;
+        System.out.println();
+    }
+}

java/java-tests/testSrc/com/intellij/refactoring/ExtractMethodTest.java

@@ -666,6 +666,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doTestReturnTypeChanged(PsiType.INT);
   }
 
+  public void testNoReturnTypesSuggested() throws Exception {
+    doTestReturnTypeChanged(PsiType.INT);
+  }
+
   public void testMultipleVarsInMethodNoReturnStatementAndAssignment() throws Exception {
     //return type should not be suggested but still 
     doTestReturnTypeChanged(PsiType.INT);