[newlib-cygwin] Cygwin: pty: Omit CSI?1004h/l from pseudo console output

[Takashi Yano]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=1bddcff4cc3d2919343cc762f77eff4c4f278513

commit 1bddcff4cc3d2919343cc762f77eff4c4f278513
Author: Takashi Yano <takashi.yano@nifty.ne.jp>
Date:   Mon Mar 9 17:33:12 2026 +0900

    Cygwin: pty: Omit CSI?1004h/l from pseudo console output
    
    "CSI?1004h" is the sequence that enables focus event report. This
    can be handle correctly by pseudo console, however, if the pty
    input is not connected to pseudo console, the focus event responses
    such as "CSI I/O" are sent to the foreground process. Due to this,
    `cat` receives these responses unexpectedly in the command below.
    
    $ cmd &
    $ cat
    
    This seems to happen since Windows 11.
    
    To avoid this, this patch removes "CSI?1004h/l" from pseudo console
    output.
    
    Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
    Reviewed-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/fhandler/pty.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler/pty.cc b/winsup/cygwin/fhandler/pty.cc
index 9868e88e5..9ea9e80ef 100644
--- a/winsup/cygwin/fhandler/pty.cc
+++ b/winsup/cygwin/fhandler/pty.cc
@@ -2733,7 +2733,8 @@ workarounds_for_pseudo_console_output (char *outbuf, DWORD rlen)
 	      }
 	    state = 0;
 	  }
-	else if (saw_question_mark && arg == 9001
+	else if (saw_question_mark
+		 && (arg == 9001 || arg == 1004)
 		 && (outbuf[i] == 'h' || outbuf[i] == 'l'))
 	  {
 	    memmove (&outbuf[start_at], &outbuf[i+1], rlen-i-1);