diff options
| -rw-r--r-- | winsup/cygwin/fhandler_console.cc | 54 |
1 files changed, 35 insertions, 19 deletions
diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc index d4c077bc6..9c490c530 100644 --- a/winsup/cygwin/fhandler_console.cc +++ b/winsup/cygwin/fhandler_console.cc @@ -1216,30 +1216,46 @@ dev_console::scroll_window (HANDLE h, int x1, int y1, int x2, int y2) return false; SMALL_RECT sr; - int toscroll = 2 + dwEnd.Y - b.srWindow.Top; - int shrink = 1 + toscroll + b.srWindow.Bottom - b.dwSize.Y; + int toscroll = dwEnd.Y - b.srWindow.Top + 1; sr.Left = sr.Right = dwEnd.X = 0; - /* Can't increment dwEnd yet since we may not have space in - the buffer. */ - SetConsoleCursorPosition (h, dwEnd); - if (shrink > 0) + + if (b.srWindow.Bottom + toscroll >= b.dwSize.Y) { - COORD c = b.dwSize; - c.Y = dwEnd.Y - shrink; - SetConsoleScreenBufferSize (h, c); - SetConsoleScreenBufferSize (h, b.dwSize); - dwEnd.Y = 0; - fillin (h); - toscroll = 2 + dwEnd.Y - b.srWindow.Top; + /* So we're at the end of the buffer and scrolling the console window + would move us beyond the buffer. What we do here is to scroll the + console buffer upward by just as much so that the current last line + becomes the last line just prior to the first window line. That + keeps the end of the console buffer intact, as desired. + + Since we're moving the console buffer under the console window in + this case, we must not move the console window. */ + SMALL_RECT br; + COORD dest; + CHAR_INFO fill; + + br.Left = 0; + br.Top = dwEnd.Y - b.srWindow.Top + 1; + br.Right = b.dwSize.X - 1; + br.Bottom = b.dwSize.Y - 1; + dest.X = dest.Y = 0; + fill.Char.AsciiChar = ' '; + fill.Attributes = current_win32_attr; + ScrollConsoleScreenBuffer (h, &br, NULL, dest, &fill); + /* Fix dwEnd to reflect the new cursor line (minus 1 to take the + increment a few lines later into account) */ + dwEnd.Y = b.dwCursorPosition.Y - 1; } - - sr.Top = sr.Bottom = toscroll; - - SetConsoleWindowInfo (h, FALSE, &sr); - + else + { + /* The reminder of the console buffer is big enough to simply move + the console window. */ + sr.Top = sr.Bottom = toscroll; + SetConsoleWindowInfo (h, FALSE, &sr); + } + /* Eventually set cursor to new end position at the top of the window. */ dwEnd.Y++; SetConsoleCursorPosition (h, dwEnd); - + /* Fix up console buffer info. */ fillin (h); return true; } |