Fix undefined behaviour on build with -D_FORTIFY_SOURCE=2

Found by tstellar@redhat.com

memcached-1.6.3-dfortify.patch

@@ -0,0 +1,51 @@
+From c65973d08c4dffbb38ce032d00b901d0ce534c6f Mon Sep 17 00:00:00 2001
+From: Tom Stellard <tstellar@redhat.com>
+Date: Mon, 30 Mar 2020 17:49:38 +0000
+Subject: [PATCH] Fix undefined behavior when compiling with
+ -D_FORTIFY_SOURCE=2
+
+When compiling with -D_FORTIFY_SOURCE=2, printf is defined as a macro,
+which makes the #ifdef TLS block in the usage() function of memcached.c
+undefined behavior.
+
+This warning was caught by compiling with clang:
+
+memcached.c:7829:2: error: embedding a directive within macro arguments has undefined behavior [-Werror,-Wembedded-directive]
+ ^
+memcached.c:7832:2: error: embedding a directive within macro arguments has undefined behavior [-Werror,-Wembedded-directive]
+ ^
+---
+ memcached.c | 11 ++++++-----
+ 1 file changed, 6 insertions(+), 5 deletions(-)
+
+diff --git a/memcached.c b/memcached.c
+index 2592b3f94..148a3b55a 100644
+--- a/memcached.c
++++ b/memcached.c
+@@ -7825,12 +7825,13 @@ static void usage(void) {
+            "-s, --unix-socket=<file>  UNIX socket to listen on (disables network support)\n"
+            "-A, --enable-shutdown     enable ascii \"shutdown\" command\n"
+            "-a, --unix-mask=<mask>    access mask for UNIX socket, in octal (default: %o)\n"
+-           "-l, --listen=<addr>       interface to listen on (default: INADDR_ANY)\n"
++           "-l, --listen=<addr>       interface to listen on (default: INADDR_ANY)\n",
++           settings.port, settings.udpport, settings.access);
+ #ifdef TLS
+-           "                          if TLS/SSL is enabled, 'notls' prefix can be used to\n"
+-           "                          disable for specific listeners (-l notls:<ip>:<port>) \n"
++    printf("                          if TLS/SSL is enabled, 'notls' prefix can be used to\n"
++           "                          disable for specific listeners (-l notls:<ip>:<port>) \n");
+ #endif
+-           "-d, --daemon              run as a daemon\n"
++    printf("-d, --daemon              run as a daemon\n"
+            "-r, --enable-coredumps    maximize core file limit\n"
+            "-u, --user=<user>         assume identity of <username> (only when run as root)\n"
+            "-m, --memory-limit=<num>  item memory in megabytes (default: %lu)\n"
+@@ -7846,7 +7847,7 @@ static void usage(void) {
+            "-P, --pidfile=<file>      save PID in <file>, only used with -d option\n"
+            "-f, --slab-growth-factor=<num> chunk size growth factor (default: %2.2f)\n"
+            "-n, --slab-min-size=<bytes> min space used for key+value+flags (default: %d)\n",
+-           settings.port, settings.udpport, settings.access, (unsigned long) settings.maxbytes / (1 << 20),
++           (unsigned long) settings.maxbytes / (1 << 20),
+            settings.maxconns, settings.factor, settings.chunk_size);
+     verify_default("udp-port",settings.udpport == 0);
+     printf("-L, --enable-largepages  try to use large memory pages (if available)\n");

memcached.spec

@@ -12,7 +12,7 @@
 
 Name:           memcached
 Version:        1.6.3
-Release:        1%{?dist}
+Release:        2%{?dist}
 Epoch:          0
 Summary:        High Performance, Distributed Memory Object Cache
 
@@ -24,6 +24,7 @@ Source1:        memcached.sysconfig
 Source2:        https://releases.pagure.org/memcached-selinux/memcached-selinux-1.0.2.tar.gz
 
 Patch1:         memcached-unit.patch
+Patch2:         memcached-1.6.3-dfortify.patch
 
 BuildRequires:  gcc libevent-devel systemd
 BuildRequires:  perl-generators
@@ -68,6 +69,7 @@ optimised for use with this version of memcached.
 # and SELinux policy sources into memcached-selinux-X.X
 %setup -q -b 2
 %patch1 -p1 -b .unit
+%patch2 -p1 -b .dfortify
 
 %build
 %configure \
@@ -173,6 +175,10 @@ fi
 %license ../%{selinuxmoduledir}/COPYING
 
 %changelog
+* Mon Apr 06 2020 Tomas Korbar <tkorbar@redhat.com> - 0:1.6.3-2
+- Fix undefined behaviour on build with -D_FORTIFY_SOURCE=2
+- Found by tstellar@redhat.com
+
 * Sun Mar 29 2020 Tomas Korbar <tkorbar@redhat.com> - 0:1.6.3-1
 - Update to 1.6.3