Whisper: Only the last topic in a multi-topic subscription gets subscribed

[dhl]

System information

Geth version: 1.8.2
OS & Version: OSX 10.3.3

Expected behaviour

After successfully subscribing to multiple topics with the shh_subscribe JSON-RPC call encrypted to key X, topics sent to key X should be delivered to the subscription.

Actual behaviour

Only messages encrypted to the last topic in the topics array is delivered to the subscription.

Steps to reproduce the behaviour

Step 1: Create an symmetric key

{"jsonrpc": "2.0", "method": "shh_generateSymKeyFromPassword", "params": ["test"], "id": 1}

Step 2: Subscribe to multiple topics with symKeyID returned from step 1

{
    "jsonrpc": "2.0",
    "method": "shh_subscribe",
    "params": [
        "messages",
        {
            "symKeyID": "some_symmetric_key_ID",
            "topics": ["0xCEFAEDFE", "0x00BAB10C"]
        }
    ],
    "id": 1
}

Step 3: Send messages to both topics with the same symKeyID returned from step 1

Step 4: Note that only the mssage for the last topic in the topics array is received.

References

This issue has also been reported to web3.js. See web3/web3.js#1361