Set the cursor to the place where a user hits tab key (#7023)

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

@@ -97,6 +97,12 @@ namespace Microsoft.PowerShell
                 // Update the progress pane only when the timer set up the update flag or WriteProgress is completed.
                 // As a result, we do not block WriteProgress and whole script and eliminate unnecessary console locks and updates.
                 _progPane.Show(_pendingProgress);
+
+                // Reset the cursor back to where it started
+                if (record.RecordType == ProgressRecordType.Completed)
+                {
+                    _progPane.Hide();
+                }
             }
         }
 

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

@@ -99,12 +99,20 @@ namespace Microsoft.PowerShell
 
                 //if the cursor is at the bottom, create screen buffer space by scrolling
                 int scrollRows = rows - ((_rawui.BufferSize.Height - 1) - _location.Y);
-                for (int i = 0; i < rows; i++)
-                {
-                    Console.Out.Write('\n');
-                }
                 if (scrollRows > 0)
                 {
+                    // The following can be possibly replaced by Console.Write ("\x1b[" + scrollRows + "S");
+                    // For details, see https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences
+
+                    // Scroll the console screen up by 'scrollRows'
+                    var bottomLocation = _location;
+                    bottomLocation.Y = _rawui.BufferSize.Height;
+                    _rawui.CursorPosition = bottomLocation;
+                    for (int i = 0; i < scrollRows; i++)
+                    {
+                        Console.Out.Write('\n');
+                    }
+
                     _location.Y -= scrollRows;
                     _savedCursor.Y -= scrollRows;
                 }

src/System.Management.Automation/engine/MshCommandRuntime.cs

@@ -2252,7 +2252,7 @@ namespace System.Management.Automation
             {
                 // Only generate these exceptions if a pipeline has already been declared as the 'writing' pipeline.
                 // Otherwise, these are probably infrastructure messages and can be ignored.
-                if (this.PipelineProcessor._permittedToWrite != null)
+                if (this.PipelineProcessor?._permittedToWrite != null)
                 {
                     throw PSTraceSource.NewInvalidOperationException(
                         PipelineStrings.WriteNotPermitted);