Address @dra27's comments.

Changes

@@ -74,9 +74,8 @@ Working version
 * #8833, `ocaml`: adhere to the XDG base directory specification to
   lookup an `.ocamlinit` file. Reads an `$XDG_CONFIG_HOME/ocaml/init.ml`
   file before trying to lookup `~/.ocamlinit`. On Windows: `%LOCALAPPDATA%`
-  is also consulted if the `XDG_CONFIG_HOME` variable is undefined or empty
-  and an appropriate fallback is implemented to lookup a HOME variable if
-  undefined and needed by the lookup procedure.
+  or %APPDATA% is also consulted if the `XDG_CONFIG_HOME` variable is
+  undefined.
   (Daniel C. Bünzli, review by David Allsopp, Armaël Guéneau and
    Nicolás Ojeda Bär)
 

man/ocaml.m

@@ -305,14 +305,16 @@ use heuristics to enable colors only if the output supports them (an
 .B XDG_CONFIG_HOME/ocaml/init.ml
 according to the XDG base directory specification lookup if it exists (on
 Windows
-.B %LOCALAPPDATA%
+.B LOCALAPPDATA
+or
+.B APPDATA
 is consulted if
 .B XDG_CONFIG_HOME
 is empty or undefined), otherwise
 .B .ocamlinit
 in the user's home directory (
 .B HOME
-variable or if undefined on Windows, an appropriate fallback).
+variable).
 You can specify a different initialization file
 by using the
 .BI \-init \ file
@@ -338,7 +340,7 @@ according to the XDG base directory specification lookup if it exists (on
 consults the TERM variable to determines the type of output terminal
 and look up its capabilities in the terminal database.
 .TP
-.B XDG_CONFIG_HOME HOME %LOCALAPPDATA% (Windows)
+.B XDG_CONFIG_HOME HOME LOCALAPPDATA (Windows) APPDATA (Windows)
 .B .ocamlinit
 lookup procedure (see above).
 .SH SEE ALSO

manual/manual/cmds/top.etex

@@ -69,10 +69,10 @@ The evaluation outcode for each phrase are not displayed.
 If the current directory does not contain an ".ocamlinit" file,
 the file "XDG_CONFIG_HOME/ocaml/init.ml" is looked up according
 to the XDG base directory specification and used instead (on Windows
-"%LOCALAPPDATA%" is consulted if "XDG_CONFIG_HOME" is empty or undefined).
-If that file doesn't exist then an [.ocamlinit] file in the
-users' home directory (determined via environment variable "HOME" or,
-if undefined on Windows, an appropriate fallback) is used if existing.
+"LOCALAPPDATA" or "APPDATA" is consulted if "XDG_CONFIG_HOME" is empty or
+undefined). If that file doesn't exist then an [.ocamlinit] file in the
+users' home directory (determined via environment variable "HOME") is
+used if existing.
 
 The toplevel system does not perform line editing, but it can
 easily be used in conjunction with an external line editor such as

toplevel/opttoploop.ml

@@ -556,24 +556,14 @@ let find_ocamlinit () =
   let getenv var = match Sys.getenv var with
     | exception Not_found -> None | "" -> None | v -> Some v
   in
-  let home_dir () = match getenv "HOME" with
+  let home_dir () = getenv "HOME" in
+  let config_dir () = match getenv "XDG_CONFIG_HOME" with
     | Some _ as v -> v
-    | None when not Sys.win32 -> None
     | None ->
-        let userprofile () = getenv "USERPROFILE" in
-        match getenv "HOMEDRIVE" with
-        | None -> userprofile ()
-        | Some homedrive ->
-            match getenv "HOMEPATH" with
-            | None -> userprofile ()
-            | Some homepath ->
-                let dir = Filename.concat homedrive homepath in
-                if Sys.file_exists dir then Some dir else userprofile ()
-  in
-  let config_dir () = match getenv "XDG_CONFIG_HOME" with
-    | Some dir -> Some dir
-    | None when Sys.win32 -> getenv "%LOCALAPPDATA%"
-    | None -> None
+        if not Sys.win32 then None else
+        match getenv "LOCALAPPDATA" with
+        | Some _ as v -> v
+        | None -> get_env "APPDATA"
   in
   let init_ml = Filename.concat "ocaml" "init.ml" in
   match exists_in_dir (config_dir ()) init_ml with

toplevel/toploop.ml

@@ -504,24 +504,14 @@ let find_ocamlinit () =
   let getenv var = match Sys.getenv var with
     | exception Not_found -> None | "" -> None | v -> Some v
   in
-  let home_dir () = match getenv "HOME" with
+  let home_dir () = getenv "HOME" in
+  let config_dir () = match getenv "XDG_CONFIG_HOME" with
     | Some _ as v -> v
-    | None when not Sys.win32 -> None
     | None ->
-        let userprofile () = getenv "USERPROFILE" in
-        match getenv "HOMEDRIVE" with
-        | None -> userprofile ()
-        | Some homedrive ->
-            match getenv "HOMEPATH" with
-            | None -> userprofile ()
-            | Some homepath ->
-                let dir = Filename.concat homedrive homepath in
-                if Sys.file_exists dir then Some dir else userprofile ()
-  in
-  let config_dir () = match getenv "XDG_CONFIG_HOME" with
-    | Some dir -> Some dir
-    | None when Sys.win32 -> getenv "%LOCALAPPDATA%"
-    | None -> None
+        if not Sys.win32 then None else
+        match getenv "LOCALAPPDATA" with
+        | Some _ as v -> v
+        | None -> get_env "APPDATA"
   in
   let init_ml = Filename.concat "ocaml" "init.ml" in
   match exists_in_dir (config_dir ()) init_ml with