Index: s-os_lib.adb
===================================================================
--- s-os_lib.adb	(revision 230522)
+++ s-os_lib.adb	(working copy)
@@ -2081,34 +2081,35 @@
       -------------------
 
       function Get_Directory (Dir : String) return String is
-         Result : String (1 .. Dir'Length + 1);
-         Length : constant Natural := Dir'Length;
-
       begin
          --  Directory given, add directory separator if needed
 
-         if Length > 0 then
-            Result (1 .. Length) := Dir;
+         if Dir'Length > 0 then
+            declare
+               Result : String   :=
+                          Normalize_Pathname (Dir, "") & Directory_Separator;
+               Last   : Positive := Result'Last - 1;
 
-            --  On Windows, change all '/' to '\'
+            begin
+               --  On Windows, change all '/' to '\'
 
-            if On_Windows then
-               for J in 1 .. Length loop
-                  if Result (J) = '/' then
-                     Result (J) := Directory_Separator;
-                  end if;
-               end loop;
-            end if;
+               if On_Windows then
+                  for J in Result'First .. Last - 1 loop
+                     if Result (J) = '/' then
+                        Result (J) := Directory_Separator;
+                     end if;
+                  end loop;
+               end if;
 
-            --  Add directory separator, if needed
+               --  Include additional directory separator, if needed
 
-            if Result (Length) = Directory_Separator then
-               return Result (1 .. Length);
-            else
-               Result (Result'Length) := Directory_Separator;
-               return Result;
-            end if;
+               if Result (Last) /= Directory_Separator then
+                  Last := Last + 1;
+               end if;
 
+               return Result (Result'First .. Last);
+            end;
+
          --  Directory name not given, get current directory
 
          else
Index: s-os_lib.ads
===================================================================
--- s-os_lib.ads	(revision 230522)
+++ s-os_lib.ads	(working copy)
@@ -505,19 +505,17 @@
       Resolve_Links  : Boolean := True;
       Case_Sensitive : Boolean := True) return String;
    --  Returns a file name as an absolute path name, resolving all relative
-   --  directories, and symbolic links. The parameter Directory is a fully
-   --  resolved path name for a directory, or the empty string (the default).
-   --  Name is the name of a file, which is either relative to the given
-   --  directory name, if Directory is non-null, or to the current working
-   --  directory if Directory is null. The result returned is the normalized
-   --  name of the file. For most cases, if two file names designate the same
-   --  file through different paths, Normalize_Pathname will return the same
-   --  canonical name in both cases. However, there are cases when this is not
-   --  true; for example, this is not true in Unix for two hard links
-   --  designating the same file.
+   --  directories, and symbolic links. If Name is a relative path, it is
+   --  interpreted relative to Directory, or to the current directory if
+   --  Directory is the empty string (the default). The result returned is
+   --  the normalized name of the file, containing no "." or ".." components,
+   --  and no duplicated directory separators. For most cases, if two file
+   --  names designate the same file through different paths,
+   --  Normalize_Pathname will return the same canonical name in both cases.
+   --  However, there are cases when this is not true; for example, this is
+   --  not true in Unix for two hard links designating the same file.
    --
-   --  On Windows, the returned path will start with a drive letter except
-   --  when Directory is not empty and does not include a drive letter. If
+   --  On Windows, the returned path will start with a drive letter. If
    --  Directory is empty (the default) and Name is a relative path or an
    --  absolute path without drive letter, the letter of the current drive
    --  will start the returned path. If Case_Sensitive is True (the default),
