[glibc/release/2.34/master] resolv: Avoid GCC 12 false positive warning [BZ #28439].

[glibc/release/2.34/master] resolv: Avoid GCC 12 false positive warning [BZ #28439].

[Florian Weimer]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=92d5c52aaac0fa8e58b92e96bf2025d6848a2845

commit 92d5c52aaac0fa8e58b92e96bf2025d6848a2845
Author: Martin Sebor <msebor@redhat.com>
Date:   Mon Oct 11 09:36:57 2021 -0600

    resolv: Avoid GCC 12 false positive warning [BZ #28439].
    
    Replace a call to sprintf with an equivalent pair of stpcpy/strcpy calls
    to avoid a GCC 12 -Wformat-overflow false positive due to recent optimizer
    improvements.
    
    (cherry picked from commit eb73b87897798de981dbbf019aa957045d768adb)

Diff:
---
 resolv/res_query.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/resolv/res_query.c b/resolv/res_query.c
index 75b0e5f2f7..5d0a68dc81 100644
--- a/resolv/res_query.c
+++ b/resolv/res_query.c
@@ -610,7 +610,9 @@ __res_context_querydomain (struct resolv_context *ctx,
 			RES_SET_H_ERRNO(statp, NO_RECOVERY);
 			return (-1);
 		}
-		sprintf(nbuf, "%s.%s", name, domain);
+		char *p = __stpcpy (nbuf, name);
+		*p++ = '.';
+		strcpy (p, domain);
 	}
 	return __res_context_query (ctx, longname, class, type, answer,
 				    anslen, answerp, answerp2, nanswerp2,