Apply suggestions from code review

Co-authored-by: R. Boujbel <rjbou@ocamlpro.com>

Author: rjbou

src/state/opamFormatUpgrade.ml

@@ -1272,38 +1272,31 @@ let upgrades root_version root config =
            if cond root config then Some v else None)
        from_root_version)
   in
-  if tdebug then
-    OpamConsole.error "hard upgrad all %s " (OpamStd.List.to_string OpamVersion.to_string all_hard_upgrades);
-  if tdebug then
-    OpamConsole.error "from_root_version %s" (OpamStd.List.to_string (fun (v,_,_) -> OpamVersion.to_string v) from_root_version);
   let hard_upg, light_upg =
     (* We take the last hard upgrade *)
     let hard_upgrades =
       List.filter (fun v ->
           OpamVersion.compare root_version v < 0)
         all_hard_upgrades
-      |> List.sort OpamVersion.compare
-      |> List.rev
+      |> List.sort (fun v v' -> -(OpamVersion.compare v v'))
     in
-    if tdebug then
-      OpamConsole.error "hard upgrades list %s " (OpamStd.List.to_string OpamVersion.to_string hard_upgrades);
     match hard_upgrades with
     | latest_hard_upgrade::_ ->
       List.partition (fun (v,_,_cond) ->
           OpamVersion.compare v latest_hard_upgrade <= 0)
         from_root_version
     | [] ->
       [],
-      (* If there is no hard upgrade, we can remove upgrade function of
-         conditional hard upgrade from light upgrade list safely *)
+      (* If there is no hard upgrade, we add a light upgrade for conditional
+         hard upgrade versions *)
       let conditional_hard_upgs =
         List.filter_map (function
             | v, _, Some _ -> Some v
             | _, _, _ -> None) from_root_version
       in
       List.map (fun (v, f, c) ->
           let f =
-            if (List.mem v conditional_hard_upgs) then
+            if OpamStd.List.mem OpamVersion.equal v conditional_hard_upgs then
               fun ~on_the_fly:_ _ conf -> conf, gtc_none
             else f
           in
@@ -1312,10 +1305,6 @@ let upgrades root_version root config =
         from_root_version
   in
   let clean (x,y,_) = (x,y) in
-  if tdebug then
-    OpamConsole.error "hard upgrades %s" (OpamStd.List.to_string (fun (v,_,_) -> OpamVersion.to_string v) hard_upg);
-  if tdebug then
-    OpamConsole.error "light upgrades %s" (OpamStd.List.to_string (fun (v,_,_) -> OpamVersion.to_string v) light_upg);
   List.map clean hard_upg, List.map clean light_upg
 
 let default_opam_root_version = v2_1_alpha