djgpp: Fix unused-but-set-variable warning

I chose to just hide this behind '#ifndef __DJGPP__', instead of listing
all the macro combinations where it *is* used.  That would make quite a
mess.

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19322)

diff --git a/crypto/bio/bss_dgram.c b/crypto/bio/bss_dgram.c
index 6ec43b1bc5b9f7169eeb63584fecca5a65bd9da5..1d31ab811cac54f23aceaa4547bb48879c7ad70f 100644 (file)
--- a/crypto/bio/bss_dgram.c
+++ b/crypto/bio/bss_dgram.c
@@ -527,7 +527,10 @@ static long dgram_ctrl(BIO *b, int cmd, long num, void *ptr)
     long ret = 1;
     int *ip;
     bio_dgram_data *data = NULL;
+# ifndef __DJGPP__
+    /* There are currently no cases where this is used on djgpp/watt32. */
     int sockopt_val = 0;
+# endif
     int d_errno;
 # if defined(OPENSSL_SYS_LINUX) && (defined(IP_MTU_DISCOVER) || defined(IP_MTU))
     socklen_t sockopt_len;      /* assume that system supporting IP_MTU is
@@ -847,22 +850,22 @@ static long dgram_ctrl(BIO *b, int cmd, long num, void *ptr)
         break;
 # endif
     case BIO_CTRL_DGRAM_SET_DONT_FRAG:
-        sockopt_val = num ? 1 : 0;
-
         switch (data->peer.sa.sa_family) {
         case AF_INET:
 # if defined(IP_DONTFRAG)
+            sockopt_val = num ? 1 : 0;
             if ((ret = setsockopt(b->num, IPPROTO_IP, IP_DONTFRAG,
                                   &sockopt_val, sizeof(sockopt_val))) < 0)
                 ERR_raise_data(ERR_LIB_SYS, get_last_socket_error(),
                                "calling setsockopt()");
 # elif defined(OPENSSL_SYS_LINUX) && defined(IP_MTU_DISCOVER) && defined (IP_PMTUDISC_PROBE)
-            if ((sockopt_val = num ? IP_PMTUDISC_PROBE : IP_PMTUDISC_DONT),
-                (ret = setsockopt(b->num, IPPROTO_IP, IP_MTU_DISCOVER,
+            sockopt_val = num ? IP_PMTUDISC_PROBE : IP_PMTUDISC_DONT;
+            if ((ret = setsockopt(b->num, IPPROTO_IP, IP_MTU_DISCOVER,
                                   &sockopt_val, sizeof(sockopt_val))) < 0)
                 ERR_raise_data(ERR_LIB_SYS, get_last_socket_error(),
                                "calling setsockopt()");
 # elif defined(OPENSSL_SYS_WINDOWS) && defined(IP_DONTFRAGMENT)
+            sockopt_val = num ? 1 : 0;
             if ((ret = setsockopt(b->num, IPPROTO_IP, IP_DONTFRAGMENT,
                                   (const char *)&sockopt_val,
                                   sizeof(sockopt_val))) < 0)
@@ -875,6 +878,7 @@ static long dgram_ctrl(BIO *b, int cmd, long num, void *ptr)
 # if OPENSSL_USE_IPV6
         case AF_INET6:
 #  if defined(IPV6_DONTFRAG)
+            sockopt_val = num ? 1 : 0;
             if ((ret = setsockopt(b->num, IPPROTO_IPV6, IPV6_DONTFRAG,
                                   (const void *)&sockopt_val,
                                   sizeof(sockopt_val))) < 0)
@@ -882,8 +886,8 @@ static long dgram_ctrl(BIO *b, int cmd, long num, void *ptr)
                                "calling setsockopt()");
 
 #  elif defined(OPENSSL_SYS_LINUX) && defined(IPV6_MTUDISCOVER)
-            if ((sockopt_val = num ? IP_PMTUDISC_PROBE : IP_PMTUDISC_DONT),
-                (ret = setsockopt(b->num, IPPROTO_IPV6, IPV6_MTU_DISCOVER,
+            sockopt_val = num ? IP_PMTUDISC_PROBE : IP_PMTUDISC_DONT;
+            if ((ret = setsockopt(b->num, IPPROTO_IPV6, IPV6_MTU_DISCOVER,
                                   &sockopt_val, sizeof(sockopt_val))) < 0)
                 ERR_raise_data(ERR_LIB_SYS, get_last_socket_error(),
                                "calling setsockopt()");