Flann 1.9.2 is not deterministic

[oleg-alexandrov]

Dear developers,

I upgraded from Flann 1.9.1 to 1.9.2, and now the results are no longer the same each time I run Flann.

I understand that Flann uses randomization, but until now the seed was always the same and the results were the same. The problem is maybe with this pull request: #424, but I am not sure.

Is there a way to FLANN so that each time it is called the results are the same? I tried setting the search params to use 1 core, but it did not help. Looks that the non-determinism is at the index building stage. Thanks.

[alexgoft]

function output is result, dists and not result, dists