FilteringIterator.hasNext advances iterator every time it is called.

[GoogleCodeExporter]

FilteringIterator.hasNext advances iterator every time it is called.

[GoogleCodeExporter]

Yes this is an issue, thanks for reporting it.

hasNext() does advance the pointer. It does not affect typical usage of the 
iterator, but it's wrong nonetheless.

But I have not been able to reproduce that particular issue with Guava. The 
following copies from a FilteringIterator into a Guava ImmutableCollection and 
the test passes:

    @Test
    public void testFilteringIterator() {
        List<String> testList = Arrays.asList("abc", "bcd", "cde");
        FilteringIterator<String> iterator = new FilteringIterator<String>(testList.iterator()) {
            @Override
            public boolean isValid(String object) {
                return true;
            }
        };
        ImmutableCollection<String> immutableCollection = ImmutableList.<String>builder().addAll(iterator).build();
        assertThat(immutableCollection.size(), is(3));
        assertThat(immutableCollection.toString(), is("[abc, bcd, cde]"));
    }

It's possible there is some other way of copying into an ImmutableCollection 
that I'm not aware of could hit this issue though. As a workaround in the 
meantime the usage above seems to work for me.

Thanks for reporting this, it will be fixed!

Original comment by [email protected] on 27 Sep 2013 at 2:16

• Changed state: Accepted

[GoogleCodeExporter]

[deleted comment]

[GoogleCodeExporter]

Sorry cut and past error.

It occurs when using ImmutableSet/List.copyOf(Iterator) as it uses the 
hasNext() to optimize the returned List / Set.  This reproduction case works 
with Guava 13 and on.  I had never attempted to use the builder in place of the 
copyOf method and so hit this right away.  

    @Test
    public void testFilteringIterator() {
        List<String> testList = Arrays.asList("abc", "bcd", "cde");
        FilteringIterator<String> iterator = new FilteringIterator<String>(testList.iterator()) {
            @Override
            public boolean isValid(String object) {
                return true;
            }
        };
        ImmutableCollection<String> immutableCollection = ImmutableList.copyOf(iterator);
        assertThat(immutableCollection.size(), is(3));
        assertThat(immutableCollection.toString(), is("[abc, bcd, cde]"));
    }

Original comment by [email protected] on 27 Sep 2013 at 5:20

[GoogleCodeExporter]

Original comment by [email protected] on 2 Oct 2013 at 9:36

• Changed state: Started

[GoogleCodeExporter]

Fixed in trunk, by applying your patch. Many thanks Gabe!

I will leave this issue open until included in the next binary release, 
hopefully next week or so.

Original comment by [email protected] on 2 Oct 2013 at 10:45

[GoogleCodeExporter]

Fixed in release 1.2.4. Many thanks!

Original comment by [email protected] on 22 Nov 2013 at 10:01

• Changed state: Fixed