git: 6c951b37170f - main - mail: add volatile in grabh()

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=6c951b37170f1fb2ae8b4827070743e61b6eaed2

commit 6c951b37170f1fb2ae8b4827070743e61b6eaed2
Author:     Lexi Winter <lexi@le-Fay.ORG>
AuthorDate: 2024-01-04 22:34:58 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2024-01-05 02:40:53 +0000

    mail: add volatile in grabh()
    
    setjmp() requires that any stack variables modified between the setjmp
    call and the longjmp() must be volatile.  This means that 'saveint' in
    grabh() must be volatile, since it's modified after the setjmp().
    Otherwise, the signal handler is not properly restored, resulting in a
    crash (SIGBUS) if ^C is typed twice while composing.
    
    PR:             276119
    Reported by:    Christopher Davidson <christopher.davidson@gmail.com>
    MFC after:      2 weeks
    Pull Request:   https://github.com/freebsd/freebsd-src/pull/993
---
 usr.bin/mail/tty.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/usr.bin/mail/tty.c b/usr.bin/mail/tty.c
index 9921c8cbd209..937a43bb3789 100644
--- a/usr.bin/mail/tty.c
+++ b/usr.bin/mail/tty.c
@@ -54,7 +54,7 @@ int
 grabh(struct header *hp, int gflags)
 {
 	struct termios ttybuf;
-	sig_t saveint;
+	volatile sig_t saveint;
 	sig_t savetstp;
 	sig_t savettou;
 	sig_t savettin;