Assign a new node after calling update_cluster_info!

If we catch a connection error and refresh the cluster topology, we need
to re-calculate what node to send the command to in the router; the node
we're using might not even be a valid node any longer.

lib/redis_client/cluster.rb

@@ -125,7 +125,6 @@ def close
 
     private
 
-
     # This API is called by redis-clustering/redis-rb, but requries further refinement before we commit
     # to making it part of redis-cluster-client's official public API.
     def watch(keys)

lib/redis_client/cluster/optimistic_locking.rb

@@ -44,8 +44,7 @@ def start_watch(keys)
 
         # We have not yet selected a node for this transaction, initially, which means we can handle
         # redirections freely initially (i.e. for the first WATCH call)
-        node = @router.find_primary_node_by_slot(@slot)
-        handle_redirection(node, retry_count: 1) do |nd|
+        handle_redirection(retry_count: 1) do |nd|
           nd.with do |c|
             c.ensure_connected_cluster_scoped(retryable: false) do
               @conn = c
@@ -72,10 +71,20 @@ def add_to_watch(keys)
         @conn.call('WATCH', *keys)
       end
 
-      def handle_redirection(node, retry_count: 1, &blk)
-        @router.handle_redirection(node, retry_count: retry_count) do |nd|
+      def handle_redirection(retry_count: 1, &blk)
+        node = @router.find_primary_node_by_slot(@slot)
+        times_block_executed = 0
+        @router.handle_redirection(node, nil, retry_count: retry_count) do |nd|
+          times_block_executed = 1
           handle_asking_once(nd, &blk)
         end
+      rescue ::RedisClient::ConnectionError
+        # Deduct the number of retries that happened _inside_ router#handle_redirection from our remaining
+        # _external_ retries. Always deduct at least one in case handle_redirection raises without trying the block.
+        retry_count -= [times_block_executed, 1].min
+        raise if retry_count < 0
+
+        retry
       end
 
       def handle_asking_once(node)

lib/redis_client/cluster/router.rb

@@ -75,7 +75,7 @@ def send_command(method, command, *args, &block) # rubocop:disable Metrics/AbcSi
 
       # @see https://redis.io/docs/reference/cluster-spec/#redirection-and-resharding Redirection and resharding
       def try_send(node, method, command, args, retry_count: 3, &block)
-        handle_redirection(node, retry_count: retry_count) do |on_node|
+        handle_redirection(node, command, retry_count: retry_count) do |on_node|
           if args.empty?
             # prevent memory allocation for variable-length args
             on_node.public_send(method, command, &block)
@@ -86,12 +86,12 @@ def try_send(node, method, command, args, retry_count: 3, &block)
       end
 
       def try_delegate(node, method, *args, retry_count: 3, **kwargs, &block)
-        handle_redirection(node, retry_count: retry_count) do |on_node|
+        handle_redirection(node, nil, retry_count: retry_count) do |on_node|
           on_node.public_send(method, *args, **kwargs, &block)
         end
       end
 
-      def handle_redirection(node, retry_count:) # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
+      def handle_redirection(node, command, retry_count:) # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
         yield node
       rescue ::RedisClient::CircuitBreaker::OpenCircuitError
         raise
@@ -120,7 +120,19 @@ def handle_redirection(node, retry_count:) # rubocop:disable Metrics/AbcSize, Me
 
         update_cluster_info!
 
-        raise if retry_count <= 0
+        # if command.nil?, then we don't have a way to know what node this command should be done on
+        # under the new topology. It might be e.g. part of a transaction which needs to be retried at a
+        # higher level.
+        raise if retry_count <= 0 || command.nil?
+
+        # Find the node to use for this command - if this fails for some reason, though, re-raise
+        # the original connection error.
+        node = begin
+          find_node(find_node_key(command), retry_count: 0)
+        rescue StandardError
+          nil
+        end
+        raise unless node
 
         retry_count -= 1
         retry