[newlib-cygwin] Cygwin: console: Add workaround for windows xterm compatible mode bug.

[newlib-cygwin] Cygwin: console: Add workaround for windows xterm compatible mode bug.

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=33a21904a702191cebf0e81b4deba2dfa10a406c

commit 33a21904a702191cebf0e81b4deba2dfa10a406c
Author: Takashi Yano <takashi.yano@nifty.ne.jp>
Date:   Mon Aug 12 22:47:42 2019 +0900

    Cygwin: console: Add workaround for windows xterm compatible mode bug.
    
    - The horizontal tab positions are broken after resizing console window.
      This seems to be a bug of xterm compatible mode of windows console.
      This workaround fixes this problem.

Diff:
---
 winsup/cygwin/fhandler_console.cc | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
index df28c7f..b46a4d5 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -327,6 +327,25 @@ fhandler_console::send_winch_maybe ()
     {
       con.scroll_region.Top = 0;
       con.scroll_region.Bottom = -1;
+      if (wincap.has_con_24bit_colors ())
+	{
+	  /* Workaround for a bug of windows xterm compatible mode. */
+	  /* The horizontal tab positions are broken after resize. */
+	  DWORD dwLen;
+	  CONSOLE_SCREEN_BUFFER_INFO sbi;
+	  GetConsoleScreenBufferInfo (get_output_handle (), &sbi);
+	  /* Clear all horizontal tabs */
+	  WriteConsole (get_output_handle (), "\033[3g", 4, &dwLen, 0);
+	  /* Set horizontal tabs */
+	  for (int col=8; col<con.dwWinSize.X; col+=8)
+	    {
+	      char buf[32];
+	      __small_sprintf (buf, "\033[%d;%dH\033H", 1, col+1);
+	      WriteConsole (get_output_handle (), buf, strlen (buf), &dwLen, 0);
+	    }
+	  /* Restore cursor position */
+	  SetConsoleCursorPosition (get_output_handle (), sbi.dwCursorPosition);
+	}
       get_ttyp ()->kill_pgrp (SIGWINCH);
       return true;
     }