[newlib-cygwin/main] Revert "Cygwin: signals: make setcontext work from signal handlers"

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=068a437e21195f9db584719c53794416ad969595

commit 068a437e21195f9db584719c53794416ad969595
Author:     Corinna Vinschen <corinna@vinschen.de>
AuthorDate: Mon Mar 10 21:24:30 2025 +0100
Commit:     Corinna Vinschen <corinna@vinschen.de>
CommitDate: Mon Mar 10 21:24:48 2025 +0100

    Revert "Cygwin: signals:  make setcontext work from signal handlers"
    
    This reverts commit c5f9eed1c045ad05e968c9a9b8fb22b1d46cd8ea.
    
    This was the wrong thing to do because it leads to signal handling
    not working after swapcontext.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/exceptions.cc | 1 -
 1 file changed, 1 deletion(-)

diff --git a/winsup/cygwin/exceptions.cc b/winsup/cygwin/exceptions.cc
index 6d8985374b9e..fe56e858727b 100644
--- a/winsup/cygwin/exceptions.cc
+++ b/winsup/cygwin/exceptions.cc
@@ -1899,7 +1899,6 @@ setcontext (const ucontext_t *ucp)
 {
   PCONTEXT ctx = (PCONTEXT) &ucp->uc_mcontext;
   set_signal_mask (_my_tls.sigmask, ucp->uc_sigmask);
-  _my_tls.incyg = true;
   RtlRestoreContext (ctx, NULL);
   /* If we got here, something was wrong. */
   set_errno (EINVAL);