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https://issues.apache.org/jira/browse/CODEC-264?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16965645#comment-16965645
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Gilles Sadowski commented on CODEC-264:
---------------------------------------
There are formatting issues in the PR (alignment, tab). It seems that tabs
were used in the original file. :-(
I'd suggest to make a PR to fix that first, but I don't know what the regular
contributors to [Codec] would recommend. Better ask on the "dev" ML. Thanks.
In general the PR associated with well-defined issue and a JIRA report should
come with a _single_ commit whose message is prefixed with the JIRA identifier,
i.e. in this case:
{noformat}
CODEC-264: Fixed sign extensions.
{noformat}
and the
[src/changes/changes.xml|https://github.com/apache/commons-codec/blob/master/src/changes/changes.xml]
file should be updated accordingly.
Similarly, unit tests that ensure that the fix is working should be either
named according to what they test (e.g. {{testHash64SignExtension}} or
something) or to the JIRA issue (e.g. {{testCodec264}}). Of course, you are
welcome to mention attribution in the commit message:
{noformat}
CODEC-264: Fixed sign extensions.
Thanks to "yonik" for documenting the issue.
{noformat}
and/or in a code comment in the unit tests Java file.
> murmur3.hash64() does not account for unsigned in arguments
> -----------------------------------------------------------
>
> Key: CODEC-264
> URL: https://issues.apache.org/jira/browse/CODEC-264
> Project: Commons Codec
> Issue Type: Bug
> Affects Versions: 1.13
> Reporter: Claude Warren
> Priority: Major
> Attachments: YonikMurmur3Tests.java
>
>
> The original murmur3_x64_128 code used unsigned int for seed arguments.
> Using the equivalent bit patterns in the commons codec version does not yield
> the same results.
> I believe this is because the commons version does not account for sign
> extension etc.
> Yonic Seeley [~yonik] has explains the issue in his implementation
> https://github.com/yonik/java_util/blob/master/src/util/hash/MurmurHash3.java
> He provides a test case to show that his code returns the same answers as the
> original C/C++ code. I modified that test to call the codec version to show
> the error.
> I have attached that test case.
> Given that the original code is in the wild I am uncertain how to fix this
> issue.
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