"error in roaringArray.readFrom: did not find expected serialCookie in header" when reading a bitmap written by roaring64 about roaring

[grantwwu]

Note: sorting the input file seems to make replication way faster. Also, here's a smaller test case (also found by @wjohnson-aurora)

roaring_error_items_2_sorted.txt

[lemire]

The bug is absolutely real.

The issue is that when deserializing a 64-bit roaring bitmap, for some reason, the code first tries to deserialize a 32-bit version. I don't know why it is done, but in the instances you have created, it gets confused. It thinks it is dealing with a 32-bit bitmap, and then everything breaks after that.

(Of course, it is not, you serialize a 64-bit roaring bitmap.)

[lemire]

Feel free to review my potential fix at #410

Note that the data is not corrupted or any such thing. It is just that the code gets confused at the deserialization stage.

[lemire]

In fact, a review would be much appreciated.

[wjohnson-aurora]

Thank you for fixing this so quickly! I can confirm that commit 94aeb2b resolves this issue.