Merge bitcoin/bitcoin#29292: rpc: improve submitpackage documentation and other improvements

78e52f663f3e3ac86260b913dad777fd7218f210 doc: rpc: fix submitpackage examples (stickies-v)
1a875d4049574730d4a53a1b68bd29b80ad96d38 rpc: update min package size error message in submitpackage (stickies-v)
f9ece258aa868d0776caa86b94e71ba05a9b287e doc: rpc: submitpackage takes sorted array (stickies-v)
17f74512f0d19cb452ed79a4bff5a222fcdb53c4 test: add bounds checking for submitpackage RPC (stickies-v)

Pull request description:

  `submitpackage` requires the package to be topologically sorted with the child being the last element in the array, but this is not documented in the RPC method or the error messages.

  Also sneaking in some other minor improvements that I found while going through the code:
  - Informing the user that `package` needs to be an array of length between `1` and `MAX_PACKAGE_COUNT` is confusing when `IsChildWithPackage()` requires that the package size >= 2. Remove this check to avoid code duplication and sending a confusing error message.
  - fixups to the `submitpackage` examples

ACKs for top commit:
  fjahr:
    re-ACK 78e52f663f3e3ac86260b913dad777fd7218f210
  instagibbs:
    ACK https://github.com/bitcoin/bitcoin/pull/29292/commits/78e52f663f3e3ac86260b913dad777fd7218f210
  achow101:
    ACK 78e52f663f3e3ac86260b913dad777fd7218f210
  glozow:
    utACK 78e52f663f3e3ac86260b913dad777fd7218f210

Tree-SHA512: a8845621bb1cbf784167fc7c82cb8ceb105868b65b26d3465f072d1c04ef3699e85a21a524ade805d423bcecbc34f7d5bff12f2c21cbd902ae1fb154193ebdc9

1 files changed, 7 insertions, 6 deletions

diff --git a/src/rpc/mempool.cpp b/src/rpc/mempool.cpp
index e6fe3c7ebd..0672ec34b3 100644
--- a/src/rpc/mempool.cpp
+++ b/src/rpc/mempool.cpp
@@ -813,13 +813,14 @@ static RPCHelpMan submitpackage()
 {
     return RPCHelpMan{"submitpackage",
         "Submit a package of raw transactions (serialized, hex-encoded) to local node.\n"
-        "The package must consist of a child with its parents, and none of the parents may depend on one another.\n"
         "The package will be validated according to consensus and mempool policy rules. If any transaction passes, it will be accepted to mempool.\n"
         "This RPC is experimental and the interface may be unstable. Refer to doc/policy/packages.md for documentation on package policies.\n"
         "Warning: successful submission does not mean the transactions will propagate throughout the network.\n"
         ,
         {
-            {"package", RPCArg::Type::ARR, RPCArg::Optional::NO, "An array of raw transactions.",
+            {"package", RPCArg::Type::ARR, RPCArg::Optional::NO, "An array of raw transactions.\n"
+                "The package must solely consist of a child and its parents. None of the parents may depend on each other.\n"
+                "The package must be topologically sorted, with the child being the last element in the array.",
                 {
                     {"rawtx", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, ""},
                 },
@@ -860,15 +861,15 @@ static RPCHelpMan submitpackage()
             },
         },
         RPCExamples{
-            HelpExampleCli("testmempoolaccept", "[rawtx1, rawtx2]") +
-            HelpExampleCli("submitpackage", "[rawtx1, rawtx2]")
+            HelpExampleRpc("submitpackage", R"(["rawtx1", "rawtx2"])") +
+            HelpExampleCli("submitpackage", R"('["rawtx1", "rawtx2"]')")
         },
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
         {
             const UniValue raw_transactions = request.params[0].get_array();
-            if (raw_transactions.size() < 1 || raw_transactions.size() > MAX_PACKAGE_COUNT) {
+            if (raw_transactions.size() < 2 || raw_transactions.size() > MAX_PACKAGE_COUNT) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER,
-                                   "Array must contain between 1 and " + ToString(MAX_PACKAGE_COUNT) + " transactions.");
+                                   "Array must contain between 2 and " + ToString(MAX_PACKAGE_COUNT) + " transactions.");
             }
 
             // Fee check needs to be run with chainstate and package context