Merge #17192: util: Add CHECK_NONFATAL and use it in src/rpc

faeb6665362e35f573ad715ade0ef2db62d71839 util: Add CHECK_NONFATAL and use it in src/rpc (MarcoFalke)

Pull request description:

  Fixes #17181

  Currently, we use `assert` in RPC code to document logic and code assumptions. However, it seems a bit extreme to abort all of Bitcoin Core on an assert failure in one of the RPC threads. I suggest to replace all `assert`s with a macro `CHECK_NONFATAL(condition)` that throws a runtime error when the condition evaluates to `false`. That runtime error will then be returned to the rpc caller and will include instructions to report the error to our issue tracker.

ACKs for top commit:
  practicalswift:
    ACK faeb6665362e35f573ad715ade0ef2db62d71839
  laanwj:
    ACK faeb6665362e35f573ad715ade0ef2db62d71839
  ryanofsky:
    Code review ACK faeb6665362e35f573ad715ade0ef2db62d71839

Tree-SHA512: 9b748715a5e0767ac11f1324a95a3a6ec672a0e0658013492219223bda83ce4b1b447fd8183bbb235f7df5ef7dddda7666ad569544b4d61cc65f232ca7a800ec

3 files changed, 14 insertions, 10 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 4bbd4aaf64..fac6bcd60d 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -10,11 +10,11 @@
 #include <chain.h>
 #include <chainparams.h>
 #include <coins.h>
-#include <node/coinstats.h>
 #include <consensus/validation.h>
 #include <core_io.h>
 #include <hash.h>
 #include <index/blockfilterindex.h>
+#include <node/coinstats.h>
 #include <policy/feerate.h>
 #include <policy/policy.h>
 #include <policy/rbf.h>
@@ -34,7 +34,6 @@
 #include <validationinterface.h>
 #include <warnings.h>
 
-#include <assert.h>
 #include <stdint.h>
 
 #include <univalue.h>
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index d289274a37..d73dd6e52d 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -3,15 +3,16 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <key_io.h>
 #include <httpserver.h>
+#include <key_io.h>
 #include <outputtype.h>
 #include <rpc/blockchain.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <script/descriptor.h>
-#include <util/system.h>
+#include <util/check.h>
 #include <util/strencodings.h>
+#include <util/system.h>
 #include <util/validation.h>
 
 #include <stdint.h>
@@ -540,6 +541,7 @@ static UniValue echo(const JSONRPCRequest& request)
         throw std::runtime_error(
             RPCHelpMan{"echo|echojson ...",
                 "\nSimply echo back the input arguments. This command is for testing.\n"
+                "\nIt will return an internal bug report when exactly 100 arguments are passed.\n"
                 "\nThe difference between echo and echojson is that echojson has argument conversion enabled in the client-side table in "
                 "bitcoin-cli and the GUI. There is no server-side difference.",
                 {},
@@ -548,6 +550,8 @@ static UniValue echo(const JSONRPCRequest& request)
             }.ToString()
         );
 
+    CHECK_NONFATAL(request.params.size() != 100);
+
     return request.params;
 }
 
diff --git a/src/rpc/util.h b/src/rpc/util.h
index 72fc7b6286..ec36956c95 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -7,14 +7,15 @@
 
 #include <node/transaction.h>
 #include <outputtype.h>
-#include <pubkey.h>
 #include <protocol.h>
+#include <pubkey.h>
 #include <rpc/protocol.h>
 #include <rpc/request.h>
 #include <script/script.h>
 #include <script/sign.h>
 #include <script/standard.h>
 #include <univalue.h>
+#include <util/check.h>
 
 #include <string>
 #include <vector>
@@ -146,7 +147,7 @@ struct RPCArg {
           m_oneline_description{oneline_description},
           m_type_str{type_str}
     {
-        assert(type != Type::ARR && type != Type::OBJ);
+        CHECK_NONFATAL(type != Type::ARR && type != Type::OBJ);
     }
 
     RPCArg(
@@ -165,7 +166,7 @@ struct RPCArg {
           m_oneline_description{oneline_description},
           m_type_str{type_str}
     {
-        assert(type == Type::ARR || type == Type::OBJ);
+        CHECK_NONFATAL(type == Type::ARR || type == Type::OBJ);
     }
 
     bool IsOptional() const;
@@ -194,14 +195,14 @@ struct RPCResult {
     explicit RPCResult(std::string result)
         : m_cond{}, m_result{std::move(result)}
     {
-        assert(!m_result.empty());
+        CHECK_NONFATAL(!m_result.empty());
     }
 
     RPCResult(std::string cond, std::string result)
         : m_cond{std::move(cond)}, m_result{std::move(result)}
     {
-        assert(!m_cond.empty());
-        assert(!m_result.empty());
+        CHECK_NONFATAL(!m_cond.empty());
+        CHECK_NONFATAL(!m_result.empty());
     }
 };