[newlib-cygwin] Cygwin: raise: align return value and error checking to Linux

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=afb7c557d2af10cdcb16c7edcc9d16224995b9e0

commit afb7c557d2af10cdcb16c7edcc9d16224995b9e0
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Mon Nov 22 12:35:39 2021 +0100

    Cygwin: raise: align return value and error checking to Linux
    
    raise(2) on Linux returns the same values and sets errno
    independent of calling kill(2) or pthread_kill(3).  Align
    code to behave the same.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/signal.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/signal.cc b/winsup/cygwin/signal.cc
index f4b468664..2cf750f5c 100644
--- a/winsup/cygwin/signal.cc
+++ b/winsup/cygwin/signal.cc
@@ -303,7 +303,12 @@ raise (int sig)
   pthread *thread = _my_tls.tid;
   if (!thread || !__isthreaded)
     return kill (myself->pid, sig);
-  return pthread_kill (thread, sig);
+
+  /* Make sure to return -1 and set errno, as on Linux. */
+  int err = pthread_kill (thread, sig);
+  if (err)
+    set_errno (err);
+  return err ? -1 : 0;
 }
 
 static int