Issue #346: Helper annotation created by subiterator may remain in CAS

- Use internal helper method from SelectFSs_impl to produce temporary annotation
- Clean up test class

uimaj-core/src/main/java/org/apache/uima/cas/impl/SelectFSs_impl.java

@@ -56,6 +56,7 @@
 import org.apache.uima.cas.text.AnnotationFS;
 import org.apache.uima.cas.text.AnnotationIndex;
 import org.apache.uima.cas.text.AnnotationPredicates;
+import org.apache.uima.jcas.JCas;
 import org.apache.uima.jcas.cas.EmptyFSList;
 import org.apache.uima.jcas.cas.FSArray;
 import org.apache.uima.jcas.cas.FSList;
@@ -1018,6 +1019,10 @@ private T[] asArray(LowLevelIterator<T> it, Class<? super T> clazz) {
   // }
 
   private Annotation makePosAnnot(int begin, int end) {
+    return makePosAnnot(jcas, begin, end);
+  }
+
+  static Annotation makePosAnnot(JCas jcas, int begin, int end) {
     if (end < begin) {
       throw new IllegalArgumentException("End value must be >= Begin value");
     }

uimaj-core/src/main/java/org/apache/uima/cas/impl/Subiterator.java

@@ -365,7 +365,7 @@ public enum BoundsUse {
       if (begin < 0) {
         begin = 0;
       }
-      coveringStartPos = new Annotation(jcas, begin, Integer.MAX_VALUE);
+      coveringStartPos = SelectFSs_impl.makePosAnnot(jcas, begin, Integer.MAX_VALUE);
     } else {
       coveringStartPos = null;
     }
@@ -759,7 +759,7 @@ public void moveToLastNoReinit() {
    */
   private void moveToJustPastBoundsAndBackup(int begin, int end,
           Predicate<Annotation> continue_going_backwards) {
-    it.moveToNoReinit(new Annotation(jcas, begin, end));
+    it.moveToNoReinit(SelectFSs_impl.makePosAnnot(jcas, begin, end));
 
     if (!it.isValid()) {
       it.moveToLastNoReinit();

uimaj-core/src/test/java/org/apache/uima/cas/impl/SubiteratorTest.java

@@ -0,0 +1,119 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.uima.cas.impl;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.contentOf;
+
+import java.io.File;
+
+import org.apache.uima.UIMAFramework;
+import org.apache.uima.analysis_engine.AnalysisEngine;
+import org.apache.uima.cas.CAS;
+import org.apache.uima.cas.FSIterator;
+import org.apache.uima.cas.test.Sentence;
+import org.apache.uima.cas.test.Token;
+import org.apache.uima.jcas.JCas;
+import org.apache.uima.resource.ResourceSpecifier;
+import org.apache.uima.test.junit_extension.JUnitExtension;
+import org.apache.uima.util.XMLInputSource;
+import org.apache.uima.util.XMLParser;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+//@formatter:off
+/**
+ * The setup:
+ *   Token (super = Annotation)
+ *   Sentence (super = Annotation)
+ *   
+ *   Annotator:  (in descr) SubIteratorAnnotator
+ */
+//@formatter:on
+public class SubiteratorTest {
+
+  private static AnalysisEngine segmenter = null;
+
+  private JCas jcas;
+
+  @BeforeAll
+  static void setupClass() throws Exception {
+    File descriptorFile = JUnitExtension.getFile("CASTests/desc/TokensAndSentences.xml");
+
+    assertThat(descriptorFile).exists();
+
+    XMLParser parser = UIMAFramework.getXMLParser();
+    ResourceSpecifier spec = (ResourceSpecifier) parser.parse(new XMLInputSource(descriptorFile));
+    segmenter = UIMAFramework.produceAnalysisEngine(spec);
+  }
+
+  @BeforeEach
+  public void setUp() throws Exception {
+    String text = contentOf(getClass().getResource("/CASTests/verjuice.txt"), UTF_8);
+
+    jcas = segmenter.newJCas();
+    jcas.setDocumentText(text);
+
+    segmenter.process(jcas);
+  }
+
+  @Test
+  public void testAnnotator() throws Exception {
+    iterateAndCheck(jcas);
+
+    iterateAndCheck(jcas);
+  }
+
+  @Test
+  public void thatTemporaryAnnotationsAreNotRetained() throws Exception {
+    var casImpl = ((CASImpl) jcas.getCas());
+    try (var ctx = casImpl.ll_forceEnableV2IdRefs(true)) {
+      var fsesBefore = new AllFSs(casImpl).getAllFSsAllViews_sofas_reachable().getAllFSsSorted();
+      var maxId = fsesBefore.stream().mapToInt(fs -> fs._id).max().getAsInt();
+
+      // This select creates a temporary annotation used to constrain the operation
+      jcas.select(Token.class).covering(0, 10).asList();
+
+      var fsesAfter = new AllFSs(casImpl).getAllFSsAllViews_sofas_reachable().getAllFSsSorted();
+      assertThat(fsesAfter) //
+              .extracting(fs -> fs.getType().getName())//
+              .containsOnly(CAS.TYPE_NAME_SOFA, CAS.TYPE_NAME_DOCUMENT_ANNOTATION,
+                      Sentence._TypeName, Token._TypeName);
+
+      // The +1 here accounts for the temporary Annotation that was created.
+      var t = new Token(jcas);
+      assertThat(t._id).isEqualTo(maxId + 2 + 1);
+    }
+  }
+
+  private void iterateAndCheck(JCas aJCas) {
+    var tokenIndex = aJCas.getAnnotationIndex(Token.class);
+    var firstSentence = aJCas.getAnnotationIndex(Sentence.class).iterator().next();
+    var tokenIterator = tokenIndex.subiterator(firstSentence);
+    var firstToken = tokenIndex.iterator().next();
+    tokenIterator.moveTo(firstToken);
+
+    // check unambiguous iterator creation
+    FSIterator<Token> it = tokenIndex.iterator(false);
+    it.moveTo(firstToken);
+  }
+}