From af6d4a423967e033cdf51e3762d0a4d14f659983 Mon Sep 17 00:00:00 2001
From: Julien Lancelot <julien.lancelot@sonarsource.com>
Date: Fri, 3 Apr 2015 15:51:28 +0200
Subject: Hasnext() should not call doNext() when iterator already closed

---
 .../org/sonar/server/util/CloseableIterator.java   |  6 +++++
 .../sonar/server/util/CloseableIteratorTest.java   | 28 ++++++++++++++++++++++
 2 files changed, 34 insertions(+)

(limited to 'server')

diff --git a/server/sonar-server/src/main/java/org/sonar/server/util/CloseableIterator.java b/server/sonar-server/src/main/java/org/sonar/server/util/CloseableIterator.java
index 44903d9a0da..c8244454baa 100644
--- a/server/sonar-server/src/main/java/org/sonar/server/util/CloseableIterator.java
+++ b/server/sonar-server/src/main/java/org/sonar/server/util/CloseableIterator.java
@@ -28,9 +28,14 @@ import java.util.NoSuchElementException;
 
 public abstract class CloseableIterator<O> implements Iterator<O>, AutoCloseable {
   private O nextObject = null;
+  boolean isClosed = false;
 
   @Override
   public final boolean hasNext() {
+    // Optimization to not call bufferNext() when already closed
+    if (isClosed) {
+      return false;
+    }
     boolean hasNext = nextObject != null || bufferNext() != null;
     if (!hasNext) {
       close();
@@ -88,6 +93,7 @@ public abstract class CloseableIterator<O> implements Iterator<O>, AutoCloseable
   public final void close() {
     try {
       doClose();
+      isClosed = true;
     } catch (Exception e) {
       Throwables.propagate(e);
     }
diff --git a/server/sonar-server/src/test/java/org/sonar/server/util/CloseableIteratorTest.java b/server/sonar-server/src/test/java/org/sonar/server/util/CloseableIteratorTest.java
index 96913c04d7f..672ff885e02 100644
--- a/server/sonar-server/src/test/java/org/sonar/server/util/CloseableIteratorTest.java
+++ b/server/sonar-server/src/test/java/org/sonar/server/util/CloseableIteratorTest.java
@@ -96,6 +96,21 @@ public class CloseableIteratorTest {
     assertThat(it.isRemoved).isTrue();
   }
 
+  @Test
+  public void has_next_should_not_call_do_next_when_already_closed() throws Exception {
+    DoNextShouldNotBeCalledWhenClosedIterator it = new DoNextShouldNotBeCalledWhenClosedIterator();
+
+    it.next();
+    it.next();
+    assertThat(it.hasNext()).isFalse();
+    // this call to hasNext close the stream
+    assertThat(it.hasNext()).isFalse();
+    assertThat(it.isClosed).isTrue();
+
+    // calling hasNext should not fail
+    it.hasNext();
+  }
+
   static class SimpleCloseableIterator extends CloseableIterator {
     int count = 0;
     boolean isClosed = false;
@@ -147,4 +162,17 @@ public class CloseableIteratorTest {
       isClosed = true;
     }
   }
+
+  static class DoNextShouldNotBeCalledWhenClosedIterator extends SimpleCloseableIterator {
+
+    @Override
+    protected Object doNext() {
+      if (!isClosed) {
+        return super.doNext();
+      } else {
+        throw new IllegalStateException("doNext should not be called when already closed");
+      }
+    }
+  }
+
 }
-- 
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