Remove pointer cast in CRPCTable::dumpArgMap

CRPCTable::dumpArgMap currently works by casting RPC command unique_id
integer field to a function pointer, and then calling the function. The
unique_id field wasn't supposed to be used this way (it's meant to be
used to detect RPC aliases), and this code segfaults in the rpc_help.py
test in multiprocess PR https://github.com/bitcoin/bitcoin/pull/10102
because wallet RPC functions aren't directly accessible from the node
process.

Fix this by adding a new GET_ARGS request mode to retrieve argument
information similar to the way the GET_HELP mode retrieves help
information.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/rpc/server.h b/src/rpc/server.h
index fe5a791e1e..03967020c2 100644
--- a/src/rpc/server.h
+++ b/src/rpc/server.h
@@ -148,7 +148,7 @@ public:
     /**
      * Return all named arguments that need to be converted by the client from string to another JSON type
      */
-    UniValue dumpArgMap() const;
+    UniValue dumpArgMap(const JSONRPCRequest& request) const;
 
     /**
      * Appends a CRPCCommand to the dispatch table.