libbb: code shrink in exec_shell()

function                                             old     new   delta
exec_shell                                           129     120      -9

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

1 files changed, 8 insertions, 6 deletions

diff --git a/libbb/run_shell.c b/libbb/run_shell.c
index c2ff69651..9bec43b7c 100644
--- a/libbb/run_shell.c
+++ b/libbb/run_shell.c
@@ -59,7 +59,7 @@ void FAST_FUNC exec_shell(const char *shell, int loginshell, const char **additi
         while (args && *args)
                 args++;
 
-        args = xmalloc(sizeof(char*) * (2 + (args - additional_args)));
+        args = xzalloc(sizeof(args[0]) * (2 + (args - additional_args)));
 
         if (!shell || !shell[0])
                 shell = DEFAULT_SHELL;
@@ -67,12 +67,11 @@ void FAST_FUNC exec_shell(const char *shell, int loginshell, const char **additi
         args[0] = bb_get_last_path_component_nostrip(shell);
         if (loginshell)
                 args[0] = xasprintf("-%s", args[0]);
-        args[1] = NULL;
+        /*args[1] = NULL; - already is */
         if (additional_args) {
-                int cnt = 1;
-                for (;;)
-                        if ((args[cnt++] = *additional_args++) == NULL)
-                                break;
+                int cnt = 0;
+                while (*additional_args)
+                        args[++cnt] = *additional_args++;
         }
 
 #if ENABLE_SELINUX
@@ -91,5 +90,8 @@ void FAST_FUNC exec_prog_or_SHELL(char **argv)
         if (argv[0]) {
                 BB_EXECVP_or_die(argv);
         }
+        /* Why login=1? Both users (nsenter and unshare) do indeed exec
+         * a _login_ shell (with dash in argv[0])!
+         */
         exec_shell(getenv("SHELL"), /*login:*/ 1, NULL);
 }