fix: text overriding was only platform specific (check platform)

Author: Lukáš Jurčík

LineEditor/getline.cs

@@ -44,6 +44,7 @@
 usingSystem.IO;
 usingSystem.Threading;
 usingSystem.Reflection;
+usingSystem.Runtime.InteropServices;
 
 namespaceMono.Terminal{
 
@@ -409,6 +410,8 @@ public static Handler Alt (char c, ConsoleKey k, KeyHandler h)
 
 staticHandler[]handlers;
 
+privatereadonlyboolisWindows;
+
 /// <summary>
 /// Initializes a new instance of the LineEditor, using the specified name for 
 /// retrieving and storing the history. The history will default to 10 entries.
@@ -467,6 +470,7 @@ public LineEditor (string name, int histsize)
 
 history=newHistory(name,histsize);
 
+isWindows=RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
 GetUnixConsoleReset();
 //if (File.Exists ("log"))File.Delete ("log");
 //log = File.CreateText ("log"); 
@@ -482,9 +486,7 @@ void GetUnixConsoleReset ()
 //
 // On Unix, we want to be able to reset the color for the pop-up completion
 //
-intp=(int)Environment.OSVersion.Platform;
-varis_unix=(p==4)||(p==128);
-if(!is_unix)
+if(isWindows)
 return;
 
 // Sole purpose of this call is to initialize the Terminfo driver
@@ -770,10 +772,10 @@ void ShowCompletions (string prefix, string [] completions)
 // Ensure we have space, determine window size
 intwindow_height=System.Math.Min(completions.Length,Console.WindowHeight/5);
 inttarget_line=Console.WindowHeight-window_height-1;
-if(Console.CursorTop>target_line){
-vardelta=Console.CursorTop-target_line+window_height;
+if(!isWindows&&Console.CursorTop>target_line){
+vardelta=Console.CursorTop-target_line;
 Console.CursorLeft=0;
-Console.CursorTop=target_line;
+Console.CursorTop=Console.WindowHeight-1;
 for(inti=0;i<delta+1;i++){
 for(intc=Console.WindowWidth;c>0;c--)
 Console.Write(" ");// To debug use ("{0}", i%10);