fix(rpc): pass blockhash into TxToJSON so that getspecialtxes could show correct instantlock/chainlock values (#5774)

## Issue being fixed or feature implemented
`instantlock` and `chainlock` are broken in `getspecialtxes`

kudos to @thephez for finding the issue

## What was done?
pass the hash and also rename the variable to self-describing

## How Has This Been Tested?
run `getspecialtxes` on a node with and without the patch

## Breaking Changes
`instantlock` and `chainlock` will show actual values and not just
`false` all the time now (not sure if that qualifies for "breaking"
though)

## Checklist:
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_

doc/release-notes-5774.md

@@ -0,0 +1,4 @@
+RPC changes
+-----------
+
+In `getspecialtxes` `instantlock` and `chainlock` fields were always `false`. They should show actual values now.

src/rpc/blockchain.cpp

@@ -2462,7 +2462,7 @@ static UniValue getspecialtxes(const JSONRPCRequest& request)
     CTxMemPool& mempool = EnsureMemPool(node);
     LLMQContext& llmq_ctx = EnsureLLMQContext(node);
 
-    uint256 hash(ParseHashV(request.params[0], "blockhash"));
+    uint256 blockhash(ParseHashV(request.params[0], "blockhash"));
 
     int nTxType = -1;
     if (!request.params[1].isNull()) {
@@ -2491,7 +2491,7 @@ static UniValue getspecialtxes(const JSONRPCRequest& request)
         }
     }
 
-    const CBlockIndex* pblockindex = chainman.m_blockman.LookupBlockIndex(hash);
+    const CBlockIndex* pblockindex = chainman.m_blockman.LookupBlockIndex(blockhash);
     if (!pblockindex) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
     }
@@ -2519,7 +2519,7 @@ static UniValue getspecialtxes(const JSONRPCRequest& request)
             case 2 :
                 {
                     UniValue objTx(UniValue::VOBJ);
-                    TxToJSON(*tx, uint256(), mempool, chainman.ActiveChainstate(), *llmq_ctx.clhandler, *llmq_ctx.isman, objTx);
+                    TxToJSON(*tx, blockhash, mempool, chainman.ActiveChainstate(), *llmq_ctx.clhandler, *llmq_ctx.isman, objTx);
                     result.push_back(objTx);
                     break;
                 }

test/functional/feature_llmq_chainlocks.py

@@ -40,8 +40,13 @@ class LLMQChainLocksTest(DashTestFramework):
         self.test_coinbase_best_cl(self.nodes[0], expected_cl_in_cb=False)
 
         # v20 is active, no quorums, no CLs - null CL in CbTx
-        self.nodes[0].generate(1)
+        nocl_block_hash = self.nodes[0].generate(1)[0]
         self.test_coinbase_best_cl(self.nodes[0], expected_cl_in_cb=True, expected_null_cl=True)
+        cbtx = self.nodes[0].getspecialtxes(nocl_block_hash, 5, 1, 0, 2)[0]
+        assert_equal(cbtx["instantlock"], False)
+        assert_equal(cbtx["instantlock_internal"], False)
+        assert_equal(cbtx["chainlock"], False)
+
 
         self.nodes[0].sporkupdate("SPORK_17_QUORUM_DKG_ENABLED", 0)
         self.wait_for_sporks_same()
@@ -55,6 +60,12 @@ class LLMQChainLocksTest(DashTestFramework):
         self.wait_for_chainlocked_block_all_nodes(self.nodes[0].getbestblockhash())
         self.test_coinbase_best_cl(self.nodes[0])
 
+        # ChainLock locks all the blocks below it so nocl_block_hash should be locked too
+        cbtx = self.nodes[0].getspecialtxes(nocl_block_hash, 5, 1, 0, 2)[0]
+        assert_equal(cbtx["instantlock"], True)
+        assert_equal(cbtx["instantlock_internal"], False)
+        assert_equal(cbtx["chainlock"], True)
+
         self.log.info("Mine many blocks, wait for chainlock")
         self.nodes[0].generate(20)
         # We need more time here due to 20 blocks being generated at once