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https://issues.apache.org/jira/browse/COLLECTIONS-802?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17526507#comment-17526507
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Ng Tsz Sum edited comment on COLLECTIONS-802 at 4/22/22 4:21 PM:
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runnable with java 8, same result as stated
{code:java}
@Test
public void iterator_remove_failed_after_hasNext() {
ReferenceMap<Integer, Integer> map = new ReferenceMap<>();
map.put(1, 2);
Iterator<Map.Entry<Integer, Integer>> iter = map.entrySet().iterator();
assertTrue(iter.hasNext());
assertTrue(iter.hasNext());
assertEquals(iter.next().getValue(), new Integer(2));
// comment below hasNext() call will pass
assertFalse(iter.hasNext());
iter.remove();
assertTrue("Expect empty but have entry: " + map.toString(),
map.isEmpty());
}
{code}
Suspect to be due to line 806 and 807 setting currentKey and currentValue to
null.
https://github.com/apache/commons-collections/blob/0b365e4c1833bf55648ca34b9dffd966c31cc69b/src/main/java/org/apache/commons/collections4/map/AbstractReferenceMap.java#L806
The whole hasNext method look strange as it is changing the state.
was (Author: samabcde):
runnable with java 8, same result as stated
{code:java}
@Test
public void iterator_remove_failed_after_hasNext() {
ReferenceMap<Integer, Integer> map = new ReferenceMap<>();
map.put(1, 2);
Iterator<Map.Entry<Integer, Integer>> iter = map.entrySet().iterator();
assertTrue(iter.hasNext());
assertTrue(iter.hasNext());
assertEquals(iter.next().getValue(), new Integer(2));
// comment below hasNext() call will pass
assertFalse(iter.hasNext());
iter.remove();
assertTrue("Expect empty but have entry: " + map.toString(),
map.isEmpty());
}
{code}
Suspect to be due to line 806 and 807 setting currentKey and currentValue to
null.
https://github.com/apache/commons-collections/blob/0b365e4c1833bf55648ca34b9dffd966c31cc69b/src/main/java/org/apache/commons/collections4/map/AbstractReferenceMap.java#L806
> ReferenceMap iterator remove violates contract
> ----------------------------------------------
>
> Key: COLLECTIONS-802
> URL: https://issues.apache.org/jira/browse/COLLECTIONS-802
> Project: Commons Collections
> Issue Type: Bug
> Components: Map
> Affects Versions: 4.4
> Reporter: Ben Manes
> Priority: Minor
> Attachments: ApacheMapTest.java
>
>
> Out of curiosity I ran Guava's testlib Map tests against the Apache types.
> This uncovered a contract bug where {{Iterator.remove()}} is invalidated by
> {{{}hasNext(){}}}, causing its call to no-op due to {{currentKey}} becoming
> {{{}null{}}}. The isolates case is,
> {code:java}
> @Test
> public void iterator_remove() {
> var map = new ReferenceMap<>();
> map.put(1, 2);
> var iter = map.entrySet().iterator();
> assertTrue(iter.hasNext());
> assertTrue(iter.hasNext());
> assertEquals(iter.next(), 1);
> assertFalse(iter.hasNext());
> iter.remove();
> assertEquals(map, Map.of());
> }{code}
> Guava's [testlib|https://github.com/google/guava/tree/master/guava-testlib]
> has good coverage for the Collections Framework and might be worth
> integrating. The simple test case that I wrote is attached.
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