Upsert doesn't work well with query where value is []byte format

[ngtuna]

What version of MongoDB are you using (mongod --version)?

v4.0.8

What version of Go are you using (go version)?

1.11.8

What operating system and processor architecture are you using (go env)?

Ubuntu 18.04.1 amd64

What did you do?

Upsert doens't work well with query where value is []byte.

Example: If I do an upsert with query := bson.M{"hash": hash} (hash [32]byte) in case of overwriting existing record. It says:

Error: E11000 duplicate key error collection: xxx.yyy index: hash_1 dup key: { : \"0xc023e09ff5f2d764fd08bfb92907d2d60cbc76d5acb8c808a26c9ed91278b489\" }"

Only work if I change hash to its string format like this: query := bson.M{"hash": hash.Hex()} - Hex() convert [32]byte to string.

Can you reproduce the issue on the latest development branch?

Haven't tried yet.