Levenshtein maximum distance is greater than length of both strings

[GoogleCodeExporter]

What steps will reproduce the problem?
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Compute the levenshtein distance between "709113544" and "1555855732":
var dmp = new diff_match_patch();
var diffs = dmp.diff_main("709113544", "1555855732");
var distance = dmp.diff_levenshtein(diffs);

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What is the expected output? 
10 (that's the length of the bigger string)
What do you see instead?
14

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What version of the product are you using? On what operating system?
Javascript version 20121119. Running in node.js, also reproduced in chrome: 
http://plnkr.co/Qgi9q4IyWmguK5mIAMxy

Original issue reported on code.google.com by andersly...@gmail.com on 22 May 2013 at 7:28

[GoogleCodeExporter]

I have the same probleme with this C# code :

            DiffMatchPatch.diff_match_patch dmpDiff = new DiffMatchPatch.diff_match_patch();
            List<DiffMatchPatch.Diff> lDiffs = dmpDiff.diff_main("considéré", "apprécié");
            int iIndex = dmpDiff.diff_levenshtein(lDiffs);
            Console.WriteLine(iIndex); // 11 ??????

According to the docs on the API home page  this is not possible. The length of 
the longer string is equal to 9.
"The minimum distance is 0 which means equality, the maximum distance is the 
length of the longer string."

Original comment by cnh...@gmail.com on 1 Oct 2013 at 10:47