Merge #12479: RPC: Add child transactions to getrawmempool verbose output

1dfb4e7d7 [Tests] Check output of parent/child tx list from getrawmempool, getmempooldescendants, getmempoolancestors, and REST interface (Conor Scott)
fc44cb108 [RPC] Add list of child transactions to verbose output of getrawmempool (Conor Scott)

Pull request description:

  `bitcoin-cli getrawmempool true` only lists a transaction's parents in the `depends` field. This change adds a `spentby` field to the json response, which lists the transaction's children in the mempool.

  Currently the only way to find child transactions is to use `getrawmempool` or make another call to `getmempooldescendants` and search the response for transactions that list the parent_txid in the `depends` list, which is inefficient.

  This change allows direct lookup of children.

  Example Output
  ```
    "9a9b5733c0d89f207908cfa3fe17809bee71f629aa095c9f8754524e29e98ba4": {
      ...other geterawmempool data...
      "wtxid": "9a9b5733c0d89f207908cfa3fe17809bee71f629aa095c9f8754524e29e98ba4",
      "depends": [
        "bdd92851d5766a42aeb62af667bb422a116cab4e032bba5e3dd6efe5b4b40aa0"
      ],
      "spentby": [
        "dc5d3ec388a9121421208738a041ac30a22163bc2e17758f2275b6c51a15ba7b"
      ]
    },
  ```

Tree-SHA512: 83da7d421c9799a40ef65af3b7fdb586d6d87385f3f2ede3afd2c311725444b858f9d91cc110422a0fa31905779934fee07211ca6fe6b746792b83692c94b3ce

1 files changed, 3 insertions, 1 deletions

diff --git a/test/functional/interface_rest.py b/test/functional/interface_rest.py
index 3e87f6d33f..8440f13a0d 100755
--- a/test/functional/interface_rest.py
+++ b/test/functional/interface_rest.py
@@ -296,8 +296,10 @@ class RESTTest (BitcoinTestFramework):
         # check that there are our submitted transactions in the TX memory pool
         json_string = http_get_call(url.hostname, url.port, '/rest/mempool/contents'+self.FORMAT_SEPARATOR+'json')
         json_obj = json.loads(json_string)
-        for tx in txs:
+        for i, tx in enumerate(txs):
             assert_equal(tx in json_obj, True)
+            assert_equal(json_obj[tx]['spentby'], txs[i+1:i+2])
+            assert_equal(json_obj[tx]['depends'], txs[i-1:i])
 
         # now mine the transactions
         newblockhash = self.nodes[1].generate(1)