terminal-util: port some generic code over to rearrange_stdio()

src/basic/fd-util.h

@@ -102,3 +102,7 @@ int acquire_data_fd(const void *data, size_t size, unsigned flags);
 int fd_move_above_stdio(int fd);
 
 int rearrange_stdio(int original_input_fd, int original_output_fd, int original_error_fd);
+
+static inline int make_null_stdio(void) {
+        return rearrange_stdio(-1, -1, -1);
+}

src/basic/terminal-util.c

@@ -628,9 +628,9 @@ int make_console_stdio(void) {
         if (r < 0)
                 log_warning_errno(r, "Failed to reset terminal, ignoring: %m");
 
-        r = make_stdio(fd);
+        r = rearrange_stdio(fd, fd, fd); /* This invalidates 'fd' both on success and on failure. */
         if (r < 0)
-                return log_error_errno(r, "Failed to duplicate terminal fd: %m");
+                return log_error_errno(r, "Failed to make terminal stdin/stdout/stderr: %m");
 
         reset_terminal_feature_caches();
 
@@ -905,40 +905,6 @@ bool on_tty(void) {
         return cached_on_tty;
 }
 
-int make_stdio(int fd) {
-        int r = 0;
-
-        assert(fd >= 0);
-
-        if (dup2(fd, STDIN_FILENO) < 0)
-                r = -errno;
-        if (dup2(fd, STDOUT_FILENO) < 0 && r >= 0)
-                r = -errno;
-        if (dup2(fd, STDERR_FILENO) < 0 && r >= 0)
-                r = -errno;
-
-        safe_close_above_stdio(fd);
-
-        /* Explicitly unset O_CLOEXEC, since if fd was < 3, then dup2() was a NOP and the bit hence possibly set. */
-        stdio_unset_cloexec();
-
-        return r;
-}
-
-int make_null_stdio(void) {
-        int null_fd, r;
-
-        null_fd = open("/dev/null", O_RDWR|O_NOCTTY|O_CLOEXEC);
-        if (null_fd < 0)
-                return -errno;
-
-        r = make_stdio(null_fd);
-
-        reset_terminal_feature_caches();
-
-        return r;
-}
-
 int getttyname_malloc(int fd, char **ret) {
         size_t l = 100;
         int r;

src/basic/terminal-util.h

@@ -90,8 +90,6 @@ bool tty_is_console(const char *tty) _pure_;
 int vtnr_from_tty(const char *tty);
 const char *default_term_for_tty(const char *tty);
 
-int make_stdio(int fd);
-int make_null_stdio(void);
 int make_console_stdio(void);
 
 int fd_columns(int fd);