[CODEC-264] murmur3.hash128() does not account for unsigned seed argument

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.13
• Fix Version/s: 1.14
• Assignee: Alex Herbert
• Reporter: Claude Warren
• Created: 02/Nov/19 08:49
• Updated: 18/Jan/20 09:27
• Resolved: 24/Nov/19 12:41

Description

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.

Issue Links

• relates to: CODEC-267 MurmurHash3.hash32() does not process trailing bytes as unsigned
• links to: Pull Request