fix for redirected console output

Author: jonsequitur

src/System.CommandLine.Rendering/EntireTerminalRegion.cs

@@ -5,7 +5,7 @@ namespace System.CommandLine.Rendering
 {
     internal class EntireTerminalRegion : Region
     {
-        public EntireTerminalRegion() : base(0, 0, Console.WindowWidth, Console.WindowHeight, false)
+        public EntireTerminalRegion() : base(0, 0, isOverwrittenOnRender: false)
         {
         }
 

src/System.CommandLine.Rendering/ScrollingTerminalRegion.cs

@@ -11,10 +11,16 @@ public ScrollingTerminalRegion() : base(0, 0, isOverwrittenOnRender: false)
 
         public override int Height => int.MaxValue;
 
-        public override int Width => Console.WindowWidth;
+        public override int Width => Console.IsOutputRedirected
+                                         ? 100
+                                         : Console.WindowWidth;
 
-        public override int Top => Console.CursorTop;
+        public override int Top => Console.IsOutputRedirected
+                                       ? 0
+                                       : Console.CursorTop;
 
-        public override int Left => Console.CursorLeft;
+        public override int Left => Console.IsOutputRedirected
+                                        ? 0
+                                        : Console.CursorLeft;
     }
-}
+}