From b57ff2c0dffffafef5c33d549c491e04620fabbe Mon Sep 17 00:00:00 2001
From: Andrii Sultanov <andrii.sultanov@cloud.com>
Date: Tue, 2 Jul 2024 09:37:29 +0100
Subject: [PATCH] fixup! Eliminate unnecessary usage of List.length to check
 for empty lists

Signed-off-by: Andrii Sultanov <andrii.sultanov@cloud.com>
---
 ocaml/xapi-cli-server/cli_operations.ml | 19 ++++++++-----------
 ocaml/xapi-cli-server/cli_printer.ml    |  3 ++-
 ocaml/xenopsd/xc/hotplug.ml             |  2 +-
 3 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/ocaml/xapi-cli-server/cli_operations.ml b/ocaml/xapi-cli-server/cli_operations.ml
index 838fb3c4b9c..a167df0f119 100644
--- a/ocaml/xapi-cli-server/cli_operations.ml
+++ b/ocaml/xapi-cli-server/cli_operations.ml
@@ -862,7 +862,6 @@ let make_param_funs getallrecs getbyuuid record class_name def_filters
         ]
       in
       let ops =
-        (* If length > 0 *)
         if settable <> [] then
           ( cli_name "param-set"
           , ["uuid"]
@@ -878,7 +877,6 @@ let make_param_funs getallrecs getbyuuid record class_name def_filters
           ops
       in
       let ops =
-        (* If length > 0 *)
         if addable <> [] then
           ops
           @ [
@@ -904,7 +902,6 @@ let make_param_funs getallrecs getbyuuid record class_name def_filters
           ops
       in
       let ops =
-        (* If length > 0 *)
         if clearable <> [] then
           ops
           @ [
@@ -2935,7 +2932,7 @@ let event_wait_gen rpc session_id classname record_matches =
     (* true if anything matches now *)
     let find_any_match recs =
       let ls = List.map record_matches recs in
-      Option.is_some (List.find_opt (fun x -> x) ls)
+      List.exists Fun.id ls
     in
     find_any_match all_recs
   in
@@ -4068,7 +4065,7 @@ let vm_install printer rpc session_id params =
             failwith "No templates matched"
         | [x] ->
             x.getref ()
-        | _ :: _ ->
+        | _ :: _ :: _ ->
             failwith "More than one matching template found"
       in
       if
@@ -4119,7 +4116,7 @@ let console fd _printer rpc session_id params =
     | [] ->
         marshal fd (Command (PrintStderr "No VM found\n")) ;
         raise (ExitWithError 1)
-    | _ :: _ ->
+    | _ :: _ :: _ ->
         marshal fd
           (Command
              (PrintStderr
@@ -4161,7 +4158,7 @@ let vm_uninstall_common fd _printer rpc session_id params vms =
         ( match r.API.vDI_VBDs with
         | [] | [_] ->
             ""
-        | _ :: _ ->
+        | _ :: _ :: _ ->
             " ** WARNING: disk is shared by other VMs"
         )
     in
@@ -4491,7 +4488,7 @@ let vm_retrieve_wlb_recommendations printer rpc session_id params =
           (Cli_printer.PTable
              [("Host(Uuid)", "Stars, RecID, ZeroScoreReason") :: table x]
           )
-    | _ :: _ ->
+    | _ :: _ :: _ ->
         failwith
           "Multiple VMs found. Operation can only be performed on one VM at a \
            time"
@@ -5102,7 +5099,7 @@ let vm_cd_eject printer rpc session_id params =
         failwith "No CDs found"
     | [_] ->
         ()
-    | _ :: _ ->
+    | _ :: _ :: _ ->
         failwith "Two or more CDs found. Please use vbd-eject"
     ) ;
     let cd = List.hd cdvbds in
@@ -5126,7 +5123,7 @@ let vm_cd_insert printer rpc session_id params =
       failwith ("CD " ^ cd_name ^ " not found")
   | [_] ->
       ()
-  | _ :: _ ->
+  | _ :: _ :: _ ->
       failwith
         ("Multiple CDs named "
         ^ cd_name
@@ -5152,7 +5149,7 @@ let vm_cd_insert printer rpc session_id params =
           )
     | [cd] ->
         Client.VBD.insert ~rpc ~session_id ~vbd:cd ~vdi:(List.hd vdis)
-    | _ :: _ ->
+    | _ :: _ :: _ ->
         failwith "Two or more empty CD devices found. Please use vbd-insert"
   in
   ignore (do_vm_op printer rpc session_id op params ["cd-name"])
diff --git a/ocaml/xapi-cli-server/cli_printer.ml b/ocaml/xapi-cli-server/cli_printer.ml
index 2df06316974..1fc1d5586fd 100644
--- a/ocaml/xapi-cli-server/cli_printer.ml
+++ b/ocaml/xapi-cli-server/cli_printer.ml
@@ -56,7 +56,8 @@ let make_printer sock minimal =
   let multi_line_xapi_minimal pval =
     match pval with
     | PTable rs ->
-        if rs <> [] && List.hd rs <> [] then
+        (* Check that all the sublists aren't empty before calling List.hd *)
+        if rs <> [] && List.for_all (fun r -> r <> []) rs then
           let names = List.map (fun r -> snd (List.hd r)) rs in
           let escaped_names = List.map escape_commas names in
           buffer := String.concat "," escaped_names :: !buffer
diff --git a/ocaml/xenopsd/xc/hotplug.ml b/ocaml/xenopsd/xc/hotplug.ml
index 08d1061160c..1eac8c8a7e0 100644
--- a/ocaml/xenopsd/xc/hotplug.ml
+++ b/ocaml/xenopsd/xc/hotplug.ml
@@ -289,7 +289,7 @@ let release (task : Xenops_task.task_handle) ~xc ~xs (x : device) =
     match domains_of_vm with
     | [] | [_] ->
         Some (get_private_data_path_of_device x)
-    | _ :: _ ->
+    | _ :: _ :: _ ->
         None
   in
   let extra_xenserver_path = extra_xenserver_path_of_device ~xs x in