Allow Finit to inherit PATH and SHELL from env.

When started as a monitor in a container, or for the test suite run from
distcheck, we must allow Finit to find its own tools like initctl.  This
should also be a more generic solution that cover more cases.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/conf.c

@@ -78,6 +78,9 @@ static uev_t etcw;
 
 static TAILQ_HEAD(, conf_change) conf_change_list = TAILQ_HEAD_INITIALIZER(conf_change_list);
 
+static char *path;
+static char *shell;
+
 static int  parse_conf(char *file, int is_rcsd);
 static void drop_changes(void);
 
@@ -326,6 +329,8 @@ void conf_parse_cmdline(int argc, char *argv[])
 	fstab      = strdup(FINIT_FSTAB);
 	finit_conf = strdup(FINIT_CONF);
 	finit_rcsd = strdup(FINIT_RCSD);
+	path       = getenv("PATH");
+	shell      = getenv("SHELL");
 
 	for (int i = 1; i < argc; i++)
 		parse_arg(argv[i]);
@@ -351,8 +356,14 @@ void conf_reset_env(void)
 		free(node);
 	}
 
-	setenv("PATH", _PATH_STDPATH, 1);
+	if (path)
-	setenv("SHELL", _PATH_BSHELL, 1);
+		setenv("PATH", path, 1);
+	else
+		setenv("PATH", _PATH_STDPATH, 1);
+	if (shell)
+		setenv("SHELL", shell, 1);
+	else
+		setenv("SHELL", _PATH_BSHELL, 1);
 	setenv("LOGNAME", "root", 1);
 	setenv("USER", "root", 1);
 }