fix: Stacks tip check only checks parent tenure

This is needed for the case where the miner is knowingly reorging the
previous tenure, which is the canonical tip, but this reorg is allowed
because of the bad timing of blocks.

Author: obycode

testnet/stacks-node/src/nakamoto_node/signer_coordinator.rs

@@ -321,6 +321,10 @@ impl SignerCoordinator {
                 )
             })?;
 
+        let parent_tenure_header =
+            NakamotoChainState::get_block_header(chain_state.db(), &parent_block_id)?
+                .ok_or(NakamotoNodeError::UnexpectedChainState)?;
+
         // this is used to track the start of the waiting cycle
         let rejections_timer = Instant::now();
         loop {
@@ -386,12 +390,14 @@ impl SignerCoordinator {
                         ));
                     }
 
-                    // Check if a new Stacks block has arrived
-                    let (canonical_stacks_tip_ch, canonical_stacks_tip_bh) =
-                        SortitionDB::get_canonical_stacks_chain_tip_hash(sortdb.conn()).unwrap();
-                    let canonical_stacks_tip =
-                        StacksBlockId::new(&canonical_stacks_tip_ch, &canonical_stacks_tip_bh);
-                    if canonical_stacks_tip != parent_block_id {
+                    // Check if a new Stacks block has arrived in the parent tenure
+                    let highest_in_tenure =
+                        NakamotoChainState::get_highest_known_block_header_in_tenure(
+                            &mut chain_state.index_conn(),
+                            &parent_tenure_header.consensus_hash,
+                        )?
+                        .ok_or(NakamotoNodeError::UnexpectedChainState)?;
+                    if highest_in_tenure.index_block_hash() != parent_block_id {
                         debug!("SignCoordinator: Exiting due to new stacks tip");
                         return Err(NakamotoNodeError::StacksTipChanged);
                     }