Merge bitcoin#28597: wallet: No BDB creation, unless -deprecatedrpc=create_bdb

fa071ae wallet: No BDB creation, unless -deprecatedrpc=create_bdb (MarcoFalke)

Bitcoin Pull request description:

  With BDB being removed soon, it seems confusing and harmful to allow users to create fresh BDB wallets going forward, as it would load them with an additional burden of having to migrate them soon after.

  Also, it would be good to allow for one release for test (and external) scripts to adapt.

  Fix all issues by introducing the `-deprecatedrpc=create_bdb` setting.

Author: d0wn3d

src/wallet/rpc/wallet.cpp

@@ -634,7 +634,9 @@ static RPCHelpMan createwallet()
             {"blank", RPCArg::Type::BOOL, RPCArg::Default{false}, "Create a blank wallet. A blank wallet has no keys or HD seed. One can be set using upgradetohd (by mnemonic) or sethdseed (WIF private key)."},
             {"passphrase", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "Encrypt the wallet with this passphrase."},
             {"avoid_reuse", RPCArg::Type::BOOL, RPCArg::Default{false}, "Keep track of coin reuse, and treat dirty and clean coins differently with privacy considerations in mind."},
-            {"descriptors", RPCArg::Type::BOOL, RPCArg::Default{true}, "Create a native descriptor wallet. The wallet will use descriptors internally to handle address creation."},
+            {"descriptors", RPCArg::Type::BOOL, RPCArg::Default{true}, "Create a native descriptor wallet. The wallet will use descriptors internally to handle address creation."
+                                                                       " Setting this to \"false\" creates a legacy wallet. This is only possible with -deprecatedrpc=create_bdb, because legacy wallet creation is deprecated and"
+                                                                       " support for creating and opening legacy wallets will be removed in a future release."},
             {"load_on_startup", RPCArg::Type::BOOL, RPCArg::Optional::OMITTED_NAMED_ARG, "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
             {"external_signer", RPCArg::Type::BOOL, RPCArg::Default{false}, "Use an external signer such as a hardware wallet. Requires -signer to be configured. Wallet creation will fail if keys cannot be fetched. Requires disable_private_keys and descriptors set to true."},
         },
@@ -679,11 +681,17 @@ static RPCHelpMan createwallet()
     if (!request.params[5].isNull() && request.params[6].isNull()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "The createwallet RPC requires specifying the 'load_on_startup' flag when param 'descriptors' is specified. Dash Core v21 introduced this requirement due to breaking changes in the createwallet RPC.");
     }
-    if (request.params[5].isNull() || request.params[5].get_bool()) {
+    if (request.params[5].isNull() || request.params[5].get_bool())
+    {
 #ifndef USE_SQLITE
         throw JSONRPCError(RPC_WALLET_ERROR, "Compiled without sqlite support (required for descriptor wallets)");
 #endif
         flags |= WALLET_FLAG_DESCRIPTORS;
+    } else {
+        if (!context.chain->rpcEnableDeprecated("create_bdb")) {
+            throw JSONRPCError(RPC_WALLET_ERROR, "BDB wallet creation is deprecated and will be removed in a future release."
+                                                 " In this release it can be re-enabled temporarily with the -deprecatedrpc=create_bdb setting.");
+        }
     }
     if (!request.params[7].isNull() && request.params[7].get_bool()) {
 #ifdef ENABLE_EXTERNAL_SIGNER

test/functional/test_framework/util.py

@@ -419,6 +419,7 @@ def write_config(config_path, *, n, chain, extra_config="", disable_autoconnect=
         f.write("upnp=0\n")
         f.write("natpmp=0\n")
         f.write("shrinkdebugfile=0\n")
+        f.write("deprecatedrpc=create_bdb\n")  # Required to run the tests
         # To reduce IO and consumed disk storage use tiny size for allocated blk and rev files
         f.write("tinyblk=1\n")
         # To improve SQLite wallet performance so that the tests don't timeout, use -unsafesqlitesync