env: don't SEGV on bare "env -"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 10 insertions, 8 deletions

diff --git a/coreutils/env.c b/coreutils/env.c
index f50a03e8b..9635d2b22 100644
--- a/coreutils/env.c
+++ b/coreutils/env.c
@@ -43,21 +43,20 @@ static const char env_longopts[] ALIGN1 =
 int env_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int env_main(int argc UNUSED_PARAM, char **argv)
 {
-        char **ep;
-        unsigned opt;
+        unsigned opts;
         llist_t *unset_env = NULL;
 
         opt_complementary = "u::";
 #if ENABLE_FEATURE_ENV_LONG_OPTIONS
         applet_long_options = env_longopts;
 #endif
-        opt = getopt32(argv, "+iu:", &unset_env);
+        opts = getopt32(argv, "+iu:", &unset_env);
         argv += optind;
-        if (*argv && LONE_DASH(argv[0])) {
-                opt |= 1;
+        if (argv[0] && LONE_DASH(argv[0])) {
+                opts |= 1;
                 ++argv;
         }
-        if (opt & 1) {
+        if (opts & 1) {
                 clearenv();
         }
         while (unset_env) {
@@ -84,8 +83,11 @@ int env_main(int argc UNUSED_PARAM, char **argv)
                 bb_simple_perror_msg_and_die(*argv);
         }
 
-        for (ep = environ; *ep; ep++) {
-                puts(*ep);
+        if (environ) { /* clearenv() may set environ == NULL! */
+                char **ep;
+                for (ep = environ; *ep; ep++) {
+                        puts(*ep);
+                }
         }
 
         fflush_stdout_and_exit(EXIT_SUCCESS);