From 62e46fff0694eabb6ace5335e505eadaea70119c Mon Sep 17 00:00:00 2001
From: Jakub Zajkowski <ja.zajko@gmail.com>
Date: Mon, 29 Jun 2026 12:37:10 +0200
Subject: [PATCH] Addressing race conditions in executing proposals

---
 node/src/components/block_validator.rs    |  9 ++++++++-
 node/src/reactor/main_reactor/validate.rs | 24 ++++++++++++++++-------
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/node/src/components/block_validator.rs b/node/src/components/block_validator.rs
index 289f0c7609..9f00f5b9e4 100644
--- a/node/src/components/block_validator.rs
+++ b/node/src/components/block_validator.rs
@@ -433,7 +433,14 @@ impl BlockValidator {
 
         pending_requests
             .into_iter()
-            .flat_map(|request| self.handle_new_request(effect_builder, request))
+            .flat_map(|request| {
+                match self.try_handle_as_existing_request(effect_builder, request) {
+                    MaybeHandled::Handled(effects) => effects,
+                    MaybeHandled::NotHandled(request) => {
+                        self.handle_new_request(effect_builder, request)
+                    }
+                }
+            })
             .collect()
     }
 
diff --git a/node/src/reactor/main_reactor/validate.rs b/node/src/reactor/main_reactor/validate.rs
index 8972956d6f..5ec2e5b42e 100644
--- a/node/src/reactor/main_reactor/validate.rs
+++ b/node/src/reactor/main_reactor/validate.rs
@@ -46,13 +46,23 @@ impl MainReactor {
 
         let execution_pre_state = self.contract_runtime.execution_pre_state();
         let next_consensus_height = self.consensus.next_executed_height();
-        if next_consensus_height != 0
-            && next_consensus_height != execution_pre_state.next_block_height()
-        {
-            warn!(
-                "Validate: misalignment of expected block height between consensus and contract runtime"
-            );
-            return ValidateInstruction::CatchUp;
+        let next_execution_height = execution_pre_state.next_block_height();
+        if next_consensus_height != 0 {
+            // A difference of exactly 1 where execution is ahead is expected: execution
+            // updates execution_pre_state synchronously, but consensus.next_executed_height
+            // only advances after the BlockAdded event propagates through handle_meta_block.
+            // Triggering CatchUp on this transient single-block gap causes a self-reinforcing
+            // loop (refresh_contract_runtime keeps the gap at 1) that takes minutes to escape.
+            let is_misaligned = next_execution_height < next_consensus_height
+                || next_execution_height > next_consensus_height.saturating_add(1);
+            if is_misaligned {
+                warn!(
+                    next_consensus_height,
+                    next_execution_height,
+                    "Validate: misalignment of expected block height between consensus and contract runtime"
+                );
+                return ValidateInstruction::CatchUp;
+            }
         }
 
         let queue_depth = self.contract_runtime.queue_depth();