Merge #17578: rpc: simplify getaddressinfo labels, deprecate previous behavior

8925df86c4df16b1070343fef8e4d238f3cc3bd1 doc: update release notes (Jon Atack)
8bb405bbadf11391ccba7b334b4cfe66dc85b390 test: getaddressinfo labels purpose deprecation test (Jon Atack)
60aba1f2f11529add115d963d05599130288ae28 rpc: simplify getaddressinfo labels, deprecate previous behavior (Jon Atack)
7851f14ccf2bcd1e9b2ad48e5e08881be06d9d21 rpc: incorporate review feedback from PR 17283 (Jon Atack)

Pull request description:

  This PR builds on #17283 (now merged) and is followed by #17585.

  It modifies the value returned by rpc getaddressinfo `labels` to an array of label name strings and deprecates the previous behavior of returning an array of JSON hash structures containing label `name` and address `purpose` key/value pairs.

  before
  ```
    "labels": [
      {
        "name": "DOUBLE SPEND",
        "purpose": "receive"
      }
  ```
  after
  ```
    "labels": [
      "DOUBLE SPEND"
    ]
  ```

  The deprecated behavior can be re-enabled by starting bitcoind with `-deprecatedrpc=labelspurpose`.

  For context, see:
  - https://github.com/bitcoin/bitcoin/pull/17283#issuecomment-554458001
  - http://www.erisian.com.au/bitcoin-core-dev/log-2019-12-13.html#l-425 (lines 425-427)
  - http://www.erisian.com.au/bitcoin-core-dev/log-2019-11-22.html#l-622

  Reviewers: This PR may be tested manually by building, then running bitcoind with and without the `-deprecatedrpc=labelspurpose` flag while verifying the rpc getaddressinfo help text and `labels` output.

  Next steps: deprecate the rpc getaddressinfo `label` field (EDIT: done in #17585) and add support for multiple labels per address. This PR will unblock those.

ACKs for top commit:
  jnewbery:
    reACK 8925df8
  promag:
    Code review ACK 8925df86c4df16b1070343fef8e4d238f3cc3bd1.
  meshcollider:
    Code review ACK 8925df86c4df16b1070343fef8e4d238f3cc3bd1

Tree-SHA512: c2b717209996da32b6484de7bb8800e7048410f9ce6afdb3e02a6866bd4a8f2c730f905fca27b10b877b91cf407f546e69e8c4feb9cd934325a6c71c166bd438

1 files changed, 25 insertions, 21 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 5978c60d84..85793ef180 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -3726,6 +3726,8 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
+    const std::string example_address = "\"bc1q09vm5lfy0j5reeulh4x5752q25uqqvz34hufdl\"";
+
             RPCHelpMan{"getaddressinfo",
                 "\nReturn information about the given bitcoin address.\n"
                 "Some of the information will only be present if the address is in the active wallet.\n",
@@ -3760,24 +3762,26 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
             "                                                         getaddressinfo output fields for the embedded address, excluding metadata (timestamp, hdkeypath,\n"
             "                                                         hdseedid) and relation to the wallet (ismine, iswatchonly).\n"
             "  \"iscompressed\" : true|false,        (boolean, optional) If the pubkey is compressed.\n"
-            "  \"label\" :  \"label\"                  (string) The label associated with the address. Defaults to \"\". Equivalent to the name field in the labels array.\n"
+            "  \"label\" :  \"label\"                  (string) The label associated with the address. Defaults to \"\". Equivalent to the label name in the labels array below.\n"
             "  \"timestamp\" : timestamp,            (number, optional) The creation time of the key, if available, expressed in " + UNIX_EPOCH_TIME + ".\n"
             "  \"hdkeypath\" : \"keypath\"             (string, optional) The HD keypath, if the key is HD and available.\n"
             "  \"hdseedid\" : \"<hash160>\"            (string, optional) The Hash160 of the HD seed.\n"
             "  \"hdmasterfingerprint\" : \"<hash160>\" (string, optional) The fingerprint of the master key.\n"
-            "  \"labels\"                            (object) An array of labels associated with the address. Currently limited to one label but returned\n"
+            "  \"labels\"                            (json object) An array of labels associated with the address. Currently limited to one label but returned\n"
             "                                               as an array to keep the API stable if multiple labels are enabled in the future.\n"
             "    [\n"
+            "      \"label name\" (string) The label name. Defaults to \"\". Equivalent to the label field above.\n\n"
+            "      DEPRECATED, will be removed in 0.21. To re-enable, launch bitcoind with `-deprecatedrpc=labelspurpose`:\n"
             "      { (json object of label data)\n"
-            "        \"name\": \"label name\" (string) The label name. Defaults to \"\". Equivalent to the label field above.\n"
-            "        \"purpose\": \"purpose\" (string) The purpose of the associated address (send or receive).\n"
-            "      },...\n"
+            "        \"name\" : \"label name\" (string) The label name. Defaults to \"\". Equivalent to the label field above.\n"
+            "        \"purpose\" : \"purpose\" (string) The purpose of the associated address (send or receive).\n"
+            "      }\n"
             "    ]\n"
             "}\n"
                 },
                 RPCExamples{
-                    HelpExampleCli("getaddressinfo", "\"bc1q09vm5lfy0j5reeulh4x5752q25uqqvz34hufdl\"") +
-                    HelpExampleRpc("getaddressinfo", "\"bc1q09vm5lfy0j5reeulh4x5752q25uqqvz34hufdl\"")
+                    HelpExampleCli("getaddressinfo", example_address) +
+                    HelpExampleRpc("getaddressinfo", example_address)
                 },
             }.Check(request);
 
@@ -3785,7 +3789,6 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
 
     UniValue ret(UniValue::VOBJ);
     CTxDestination dest = DecodeDestination(request.params[0].get_str());
-
     // Make sure the destination is valid
     if (!IsValidDestination(dest)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address");
@@ -3811,24 +3814,18 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
 
     ret.pushKV("iswatchonly", bool(mine & ISMINE_WATCH_ONLY));
 
-    // Return DescribeWalletAddress fields.
-    // Always returned: isscript, ischange, iswitness.
-    // Optional: witness_version, witness_program, script, hex, pubkeys (array),
-    // sigsrequired, pubkey, embedded, iscompressed.
     UniValue detail = DescribeWalletAddress(pwallet, dest);
     ret.pushKVs(detail);
 
     // Return label field if existing. Currently only one label can be
     // associated with an address, so the label should be equivalent to the
-    // value of the name key/value pair in the labels hash array below.
+    // value of the name key/value pair in the labels array below.
     if (pwallet->mapAddressBook.count(dest)) {
         ret.pushKV("label", pwallet->mapAddressBook[dest].name);
     }
 
     ret.pushKV("ischange", pwallet->IsChange(scriptPubKey));
 
-    // Fetch KeyMetadata, if present, for the timestamp, hdkeypath, hdseedid,
-    // and hdmasterfingerprint fields.
     ScriptPubKeyMan* spk_man = pwallet->GetScriptPubKeyMan(scriptPubKey);
     if (spk_man) {
         if (const CKeyMetadata* meta = spk_man->GetMetadata(dest)) {
@@ -3841,15 +3838,22 @@ UniValue getaddressinfo(const JSONRPCRequest& request)
         }
     }
 
-    // Return a labels array containing a hash of key/value pairs for the label
-    // name and address purpose. The name value is equivalent to the label field
-    // above. Currently only one label can be associated with an address, but we
-    // return an array so the API remains stable if we allow multiple labels to
-    // be associated with an address in the future.
+    // Return a `labels` array containing the label associated with the address,
+    // equivalent to the `label` field above. Currently only one label can be
+    // associated with an address, but we return an array so the API remains
+    // stable if we allow multiple labels to be associated with an address in
+    // the future.
+    //
+    // DEPRECATED: The previous behavior of returning an array containing a JSON
+    // object of `name` and `purpose` key/value pairs has been deprecated.
     UniValue labels(UniValue::VARR);
     std::map<CTxDestination, CAddressBookData>::iterator mi = pwallet->mapAddressBook.find(dest);
     if (mi != pwallet->mapAddressBook.end()) {
-        labels.push_back(AddressBookDataToJSON(mi->second, true));
+        if (pwallet->chain().rpcEnableDeprecated("labelspurpose")) {
+            labels.push_back(AddressBookDataToJSON(mi->second, true));
+        } else {
+            labels.push_back(mi->second.name);
+        }
     }
     ret.pushKV("labels", std::move(labels));