fix 'cannot resolve old cursor' error

docs/release-notes/change-log.md

@@ -13,6 +13,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Server
 
+* Fix "cannot resolve 'old cursor' from files in passthrough mode" error on some requests with an old cursor
 * Fix handling of 'special case' substreams module with only "params" as its input: should not skip this execution (used in graph-node for head tracking) 
   -> empty files in module cache with hash `d3b1920483180cbcd2fd10abcabbee431146f4c8` should be deleted for consistency
 

pipeline/resolve.go

@@ -82,6 +82,12 @@ func BuildRequestDetails(
 		req.LinearGateBlockNum = req.ResolvedStartBlockNum
 	}
 
+	// if we start under the linearHandoff, it means we are in an irreversible section of the chain,
+	// the cursor has been resolved to 'resolvedStartBlockNum' and 'undoSignal', so it is not needed anymore
+	if req.ResolvedStartBlockNum < linearHandoff {
+		req.ResolvedCursor = ""
+	}
+
 	return
 }