Guard ProgressPane for pseudo-TTYs

Again due to the fact that relying on Console.IsOutputRedirected (as
System.Console does for these APIs) causes bugs when pseudo-TTYs are
used (since the output is not redirected, but the APIs nonetheless can't
be used properly). So we ran into a problem where the value of CursorTop
and Console.BufferHeight were lies, and so we accidentally attempted to
set it numbers below zero. Guard everything.

src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleHostRawUserInterface.cs

@@ -1577,7 +1577,8 @@ namespace Microsoft.PowerShell
         public override Coordinates CursorPosition
         {
             get { return new Coordinates(Console.CursorLeft, Console.CursorTop); }
-            set { Console.SetCursorPosition(value.X, value.Y); }
+            set { Console.SetCursorPosition(value.X < 0 ? 0 : value.X,
+                                            value.Y < 0 ? 0 : value.Y); }
         }
 
         /// <summary>
@@ -1796,54 +1797,49 @@ namespace Microsoft.PowerShell
         public override void SetBufferContents(Coordinates origin,
                                                BufferCell[,] contents)
         {
-            //if there are no contents, there is nothing to set the buffer to 
+            //if there are no contents, there is nothing to set the buffer to
             if (contents == null)
             {
                 PSTraceSource.NewArgumentNullException("contents");
             }
 
-            //variables to traverse through the buffer
-            int cursorX = origin.X; 
-            int cursorY = origin.Y;
-
             //if the cursor is on the last line, we need to make more space to print the specified buffer
-            if (cursorY == Console.BufferHeight -1 && cursorX >= Console.BufferWidth)
+            if (origin.Y == BufferSize.Height - 1 && origin.X >= BufferSize.Width)
-            {   
+            {
-                //for each row in the buffer, create a new line    
+                //for each row in the buffer, create a new line
                 int rows = contents.GetLength(0);
-                for (int i=0; i < rows; i++)
+                ScrollBuffer(rows);
+                // for each row in the buffer, move the cursor y up to the beginning of the created blank space
+                // but not above zero
+                if (origin.Y >= rows)
                 {
-                    ScrollBuffer(1);
+                    origin.Y -= rows;
                 }
-
-                //for each row in the buffer, move the cursor y up to the beginning of the created blank space
-                cursorY -= rows;
             }
 
-           //iterate through the buffer to set 
+            //iterate through the buffer to set
             foreach (var charitem in contents)
             {
-                //set the cursor to false to prevent cursor flicker 
+                //set the cursor to false to prevent cursor flicker
                 Console.CursorVisible = false;
-                
-                //if x is exceeding buffer width, reset to the next line                                   
-                if (cursorX >= Console.BufferWidth) 
-                {
-                    cursorX = 1; 
-                }            
 
-                //write the character from contents 
+                //if x is exceeding buffer width, reset to the next line
+                if (origin.X >= BufferSize.Width)
+                {
+                    origin.X = 1;
+                }
+
+                //write the character from contents
                 Console.Out.Write(charitem.Character);
 
                 //advance the character one position
-                cursorX++;
+                origin.X++;
-            }            
+            }
 
             //reset the cursor to the original position
-            Console.SetCursorPosition(cursorX, cursorY);
+            CursorPosition = origin;
-            //reset the cursor to visible                
+            //reset the cursor to visible
-            Console.CursorVisible = true;                    
+            Console.CursorVisible = true;
-
         }
 
         /// <summary>

src/Microsoft.PowerShell.ConsoleHost/host/msh/ProgressPane.cs

@@ -102,32 +102,29 @@ namespace Microsoft.PowerShell
                 location.X = 0;
                 location.Y = Math.Min(location.Y + 2, bufSize.Height);
 
-                if (System.Management.Automation.Platform.IsWindows)
+#if UNIX
-                {
+                // replace the saved region in the screen buffer with our progress display
-                    // Save off the current contents of the screen buffer in the region that we will occupy
+                location = rawui.CursorPosition;
-                    savedRegion =
-                        rawui.GetBufferContents(
-                            new Rectangle(location.X, location.Y, location.X + cols - 1, location.Y + rows - 1));
-                }        
 
-                //Platform is either OSX or Linux
+                //set the cursor position back to the beginning of the region to overwrite write-progress
-                else
+                //if the cursor is at the bottom, back it up to overwrite the previous write progress
+                if (location.Y >= rawui.BufferSize.Height - rows)
                 {
-                    // replace the saved region in the screen buffer with our progress display
+                    Console.Out.Write('\n');
-                    location.X = rawui.CursorPosition.X;
+                    if (location.Y >= rows)
-                    location.Y = rawui.CursorPosition.Y;
-                    
-                    //set the cursor position back to the beginning of the region to overwrite write-progress
-                    //if the cursor is at the bottom, back it up to overwrite the previous write progress
-                    if (location.Y >= Console.BufferHeight - rows)
                     {
-                        Console.Out.Write('\n');
                         location.Y -= rows;
                     }
-                    
-                    Console.SetCursorPosition(location.X, location.Y);
                 }
-                
+
+                rawui.CursorPosition = location;
+#else
+                // Save off the current contents of the screen buffer in the region that we will occupy
+                savedRegion =
+                    rawui.GetBufferContents(
+                        new Rectangle(location.X, location.Y, location.X + cols - 1, location.Y + rows - 1));
+#endif
+
                 // replace the saved region in the screen buffer with our progress display
                 rawui.SetBufferContents(location, tempProgressRegion);
             }