Merge pull request #17912 from MinaProtocol/cjjdespres/root-backing-detection-fix

Fix epoch snapshot loading when first booting with ledger sync enabled

Author: cjjdespres

src/lib/consensus/proof_of_stake.ml

@@ -461,7 +461,7 @@ module Make_str (A : Wire_types.Concrete) = struct
       let create_epoch_ledger ~config ~context:(module Context : CONTEXT)
           ~genesis_epoch_ledger =
         let open Context in
-        if Mina_ledger.Ledger.Root.Config.exists_backing config then (
+        if Mina_ledger.Ledger.Root.Config.exists_any_backing config then (
           [%log info]
             ~metadata:
               [ ("config", Mina_ledger.Ledger.Root.Config.to_yojson config) ]

src/lib/mina_ledger/root.ml

@@ -86,6 +86,12 @@ struct
       | Converting_db_config { primary_directory; converting_directory } ->
           file_exists primary_directory && file_exists converting_directory
 
+    let exists_any_backing = function
+      | Stable_db_config path ->
+          file_exists path
+      | Converting_db_config { primary_directory; converting_directory = _ } ->
+          file_exists primary_directory
+
     let with_directory ~backing_type ~directory_name =
       match backing_type with
       | Stable_db ->

src/lib/mina_ledger/root.mli

@@ -90,6 +90,10 @@ module Make
     (** Test if a root ledger backing already exists with this config *)
     val exists_backing : t -> bool
 
+    (** Test if a root ledger backing already exists with this config, ignoring
+        the specific backing type of the root *)
+    val exists_any_backing : t -> bool
+
     (** Delete a backing of any type that might exist with this config, if 
         present. this function will try any backing type even if it didn't match
         up with one provided in the config *)

src/lib/mina_ledger/test/test_mina_ledger.ml

@@ -115,7 +115,7 @@ module Root_test = struct
         in
         L.Root.Config.move_backing_exn ~src:config ~dst:config_moved ;
         assert (
-          (not (L.Root.Config.exists_backing config))
+          (not (L.Root.Config.exists_any_backing config))
           && L.Root.Config.exists_backing config_moved
           || failwith "Config is not moved" ) ;
         let root_moved =