[newlib-cygwin] Cygwin: pty: Discard CSI > Pm m sequence from native windows apps.

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=8121b606e843c001d5ca5213d24099e04ebc62ca

commit 8121b606e843c001d5ca5213d24099e04ebc62ca
Author: Takashi Yano via Cygwin-patches <cygwin-patches@cygwin.com>
Date:   Tue Jun 30 20:12:13 2020 +0900

    Cygwin: pty: Discard CSI > Pm m sequence from native windows apps.
    
    - If vim is started from WSL (Ubuntu) which is executed in pseudo
      console in mintty, shift key and ctrl key do not work. Though
      this issue is similar to the issue resolved by commit
      4527541ec66af8d82bb9dba5d25afdf489d71271, that commit is not
      effective for this issue. This patch fixes the issue by discarding
      "CSI > Pm m" in fhandler_pty_master::pty_master_fwd_thread().

Diff:
---
 winsup/cygwin/fhandler_tty.cc | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 126249d9f..0f95cec2e 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -3316,6 +3316,34 @@ fhandler_pty_master::pty_master_fwd_thread ()
 		continue;
 	      }
 
+	  /* Remove CSI > Pm m */
+	  state = 0;
+	  start_at = 0;
+	  for (DWORD i=0; i<rlen; i++)
+	    if (outbuf[i] == '\033')
+	      {
+		start_at = i;
+		state = 1;
+		continue;
+	      }
+	    else if ((state == 1 && outbuf[i] == '[') ||
+		     (state == 2 && outbuf[i] == '>'))
+	      {
+		state ++;
+		continue;
+	      }
+	    else if (state == 3 && (isdigit (outbuf[i]) || outbuf[i] == ';'))
+	      continue;
+	    else if (state == 3 && outbuf[i] == 'm')
+	      {
+		memmove (&outbuf[start_at], &outbuf[i+1], rlen-i-1);
+		rlen = wlen = start_at + rlen - i - 1;
+		state = 0;
+		continue;
+	      }
+	    else
+	      state = 0;
+
 	  size_t nlen;
 	  char *buf = convert_mb_str
 	    (get_ttyp ()->term_code_page, &nlen, CP_UTF8, ptr, wlen);