From e47186db90c91bf86902e751b26245d671a66d56 Mon Sep 17 00:00:00 2001
From: Eric <5089238+emizzle@users.noreply.github.com>
Date: Tue, 11 Nov 2025 12:04:50 +1100
Subject: [PATCH] fix: decrease block retry count when no peers found

There is a limitation in `downloadInternal` that infinitely loops for peers when attempting to download a block if the node does not have peers. Currently, the block retry counter is only decremented if there exists peers and a download attempt is made, otherwise the loop will continue until peers are found, ad infinium. This fix decrements the retry counter on each loop that no peers are found.
---
 codex/blockexchange/engine/engine.nim | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/codex/blockexchange/engine/engine.nim b/codex/blockexchange/engine/engine.nim
index 962de133..73db0d63 100644
--- a/codex/blockexchange/engine/engine.nim
+++ b/codex/blockexchange/engine/engine.nim
@@ -371,6 +371,12 @@ proc downloadInternal(
           break
         # If we still don't have the block, we'll go for another cycle.
         trace "No peers for block, will retry shortly"
+        # Without decremeting the retries count, this would infinitely loop
+        # trying to find peers.
+        self.pendingBlocks.decRetries(address)
+        # `searchForNewPeers` will do nothing if DiscoveryRateLimit has not
+        # elapsed, so we should wait to avoid a noop
+        await sleepAsync(DiscoveryRateLimit)
         continue
 
       # Once again, it might happen that the block was requested to a peer