[newlib-cygwin/cygwin-3_3-branch] Cygwin: termios: Ensure detection of GDB inferior in process_sigs().

[Takashi Yano <tyan0@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=ded470093e5973a484ea0fff683d7b8420e2267d

commit ded470093e5973a484ea0fff683d7b8420e2267d
Author: Takashi Yano <takashi.yano@nifty.ne.jp>
Date:   Mon Feb 28 07:24:45 2022 +0900

    Cygwin: termios: Ensure detection of GDB inferior in process_sigs().
    
    - In some situations, some cygwin processes might wrongly identified
      as GDB inferior. This patch ensures the detection of GDB inferior.

Diff:
---
 winsup/cygwin/fhandler_termios.cc  | 12 ++++++------
 winsup/cygwin/include/sys/cygwin.h |  1 +
 winsup/cygwin/pinfo.cc             |  2 ++
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/winsup/cygwin/fhandler_termios.cc b/winsup/cygwin/fhandler_termios.cc
index f82ac76dc..028210d98 100644
--- a/winsup/cygwin/fhandler_termios.cc
+++ b/winsup/cygwin/fhandler_termios.cc
@@ -345,7 +345,8 @@ fhandler_termios::process_sigs (char c, tty* ttyp, fhandler_termios *fh)
 		     without pcon enabled. In this case, the inferior is not
 		     cygwin process list. PID_NEW_PG is set as a marker for
 		     GDB with non-cygwin inferior in pty code.
-	 !PID_CYGPARENT: check this for GDB with cygwin inferior. */
+	 !PID_CYGPARENT: check this for GDB with cygwin inferior or
+			 cygwin apps started from non-cygwin shell. */
       if (c == '\003' && p && p->ctty == ttyp->ntty && p->pgid == pgid
 	  && ((p->process_state & PID_NOTCYGWIN)
 	      || (p->process_state & PID_NEW_PG)
@@ -408,13 +409,12 @@ fhandler_termios::process_sigs (char c, tty* ttyp, fhandler_termios *fh)
 	  if (p->process_state & PID_TTYIN)
 	    cyg_reader = true; /* Theh process is reading the tty */
 	  if (!p->cygstarted && !(p->process_state & PID_NOTCYGWIN)
-	      && (p != myself || being_debugged ())
-	      && cyg_leader) /* inferior is cygwin app */
-	    with_debugger = true;
+	      && (p->process_state & PID_DEBUGGED))
+	    with_debugger = true; /* inferior is cygwin app */
 	  if (!(p->process_state & PID_NOTCYGWIN)
 	      && (p->process_state & PID_NEW_PG) /* Check marker */
-	      && p->pid == pgid) /* inferior is non-cygwin app */
-	    with_debugger_nat = true;
+	      && p->pid == pgid)
+	    with_debugger_nat = true; /* inferior is non-cygwin app */
 	}
     }
   if ((with_debugger || with_debugger_nat) && need_discard_input)
diff --git a/winsup/cygwin/include/sys/cygwin.h b/winsup/cygwin/include/sys/cygwin.h
index ac55ab09c..c9d4599a3 100644
--- a/winsup/cygwin/include/sys/cygwin.h
+++ b/winsup/cygwin/include/sys/cygwin.h
@@ -276,6 +276,7 @@ enum
   PID_PROCINFO	       = 0x08000, /* caller just asks for process info */
   PID_NEW_PG	       = 0x10000, /* Process created with
 				     CREATE_NEW_PROCESS_GROUOP flag */
+  PID_DEBUGGED	       = 0x20000, /* Process being debugged */
   PID_EXITED	       = 0x40000000, /* Free entry. */
   PID_REAPED	       = 0x80000000  /* Reaped */
 };
diff --git a/winsup/cygwin/pinfo.cc b/winsup/cygwin/pinfo.cc
index bb7c16547..5e04ea3da 100644
--- a/winsup/cygwin/pinfo.cc
+++ b/winsup/cygwin/pinfo.cc
@@ -106,6 +106,8 @@ pinfo_init (char **envp, int envc)
 
   myself->process_state |= PID_ACTIVE;
   myself->process_state &= ~(PID_INITIALIZING | PID_EXITED | PID_REAPED);
+  if (being_debugged ())
+    myself->process_state |= PID_DEBUGGED;
   myself.preserve ();
   debug_printf ("pid %d, pgid %d, process_state %y",
 		myself->pid, myself->pgid, myself->process_state);