Don't SetCursorPosition when not Rendered.

PSReadLine/Render.cs

@@ -61,6 +61,7 @@ class RenderData
  };
  private int _initialX;
  private int _initialY;
+ private bool _waitingToRender;
 
  private ConsoleColor _initialForeground;
  private ConsoleColor _initialBackground;
@@ -112,6 +113,7 @@ private void Render()
  _tokens = null;
  _ast = null;
  _parseErrors = null;
+ _waitingToRender = true;
  return;
  }
 
@@ -816,6 +818,7 @@ void UpdateColorsIfNecessary(string newColor)
  // TODO: set WindowTop if necessary
 
  _lastRenderTime.Restart();
+ _waitingToRender = false;
  }
 
  private static string Spaces(int cnt)
@@ -980,37 +983,44 @@ private void RecomputeInitialCoords()
 
  private void MoveCursor(int newCursor)
  {
- // In case the buffer was resized
- RecomputeInitialCoords();
- _previousRender.bufferWidth = _console.BufferWidth;
- _previousRender.bufferHeight = _console.BufferHeight;
-
- var point = ConvertOffsetToPoint(newCursor);
- if (point.Y < 0)
+ // Only update screen cursor if the buffer is fully rendered.
+ if (!_waitingToRender)
  {
- Ding();
- return;
- }
+ // In case the buffer was resized
+ RecomputeInitialCoords();
+ _previousRender.bufferWidth = _console.BufferWidth;
+ _previousRender.bufferHeight = _console.BufferHeight;
 
-if (point.Y == _console.BufferHeight)
-{
-// The cursor top exceeds the buffer height, so adjust the initial cursor
-// position and the to-be-set cursor position for scrolling up the buffer.
-_initialY -= 1;
-point.Y -= 1;
+ var point = ConvertOffsetToPoint(newCursor);
+ if (point.Y < 0)
+{
+ Ding();
+ return;
+}
 
- // Insure the cursor is on the last line of the buffer prior
- // to issuing a newline to scroll the buffer.
- _console.SetCursorPosition(point.X, point.Y);
+ if (point.Y == _console.BufferHeight)
+ {
+ // The cursor top exceeds the buffer height, so adjust the initial cursor
+ // position and the to-be-set cursor position for scrolling up the buffer.
+ _initialY -= 1;
+ point.Y -= 1;
 
- // Scroll up the buffer by 1 line.
- _console.Write("\n");
- }
- else
- {
- _console.SetCursorPosition(point.X, point.Y);
+ // Insure the cursor is on the last line of the buffer prior
+ // to issuing a newline to scroll the buffer.
+ _console.SetCursorPosition(point.X, point.Y);
+
+ // Scroll up the buffer by 1 line.
+ _console.Write("\n");
+ }
+ else
+ {
+ _console.SetCursorPosition(point.X, point.Y);
+ }
  }
 
+ // While waiting to render, and a keybinding has occured that is moving the cursor,
+ // converting offset to point could potentially result in an invalid screen position,
+ // but the insertion point should reflect the move.
  _current = newCursor;
  }