[newlib-cygwin] Cygwin: pty: Fix a bug in the code removing set window title sequence.

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=6871c8418d102c8cfc6185757210d5c7f2dd4d46

commit 6871c8418d102c8cfc6185757210d5c7f2dd4d46
Author: Takashi Yano via Cygwin-patches <cygwin-patches@cygwin.com>
Date:   Mon Aug 31 21:02:13 2020 +0900

    Cygwin: pty: Fix a bug in the code removing set window title sequence.
    
    - Commit 4e08fe42c9f3fdba63a57a8e3a6d705c4e10f50f has a bug which
      may cause infinite loop in pty_master_fwd_thread(). This patch
      fixes the issue.

Diff:
---
 winsup/cygwin/fhandler_tty.cc | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index e4e94f114..8bf39c3e6 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -2168,15 +2168,12 @@ fhandler_pty_master::pty_master_fwd_thread ()
 	      /* Remove Set title sequence */
 	      char *p0, *p1;
 	      p0 = outbuf;
-	      while ((p0 = (char *) memmem (p0, rlen, "\033]0;", 4)))
+	      while ((p0 = (char *) memmem (p0, rlen, "\033]0;", 4))
+		     && (p1 = (char *) memchr (p0, '\007', rlen-(p0-outbuf))))
 		{
-		  p1 = (char *) memchr (p0, '\007', rlen - (p0 - outbuf));
-		  if (p1)
-		    {
-		      memmove (p0, p1 + 1, rlen - (p1 + 1 - outbuf));
-		      rlen -= p1 + 1 - p0;
-		      wlen = rlen;
-		    }
+		  memmove (p0, p1 + 1, rlen - (p1 + 1 - outbuf));
+		  rlen -= p1 + 1 - p0;
+		  wlen = rlen;
 		}
 	    }
 	  /* Remove CSI > Pm m */