From 300437197350ee4eb6d5f75b3cb8c35a7b9f29ed Mon Sep 17 00:00:00 2001
From: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Thu, 8 Jul 2021 03:25:48 +0000
Subject: [PATCH] Fix build on Ubuntu 21 (#855)

The `-Wunused-result` warning for setuid(0) call was observed on Ubuntu
21.04 (when cross compiling Squid for Ubuntu 21.10).

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
 src/tools.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/tools.cc b/src/tools.cc
index b0fb52ff67..00d77cc4c1 100644
--- a/src/tools.cc
+++ b/src/tools.cc
@@ -582,7 +582,10 @@ enter_suid(void)
     }
 #else
 
-    setuid(0);
+    if (setuid(0) < 0) {
+        const auto xerrno = errno;
+        debugs(21, 3, "setuid(0) failed: " << xstrerr(xerrno));
+    }
 #endif
 #if HAVE_PRCTL && defined(PR_SET_DUMPABLE)
     /* Set Linux DUMPABLE flag */
-- 
2.47.2