diff --git a/src/indent.c b/src/indent.c
index 4ba31d2..e7de005 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -869,11 +869,15 @@
 
 #if defined(FEAT_LINEBREAK) || defined(PROTO)
 /*
+ * Check "briopt" as 'breakindentopt' and update the members of "wp".
  * This is called when 'breakindentopt' is changed and when a window is
  * initialized.
+ * Returns FAIL for failure, OK otherwise.
  */
     int
-briopt_check(win_T *wp)
+briopt_check(
+    char_u	*briopt,	// when NULL: use "wp->w_p_briopt"
+    win_T	*wp)		// when NULL: only check "briopt"
 {
     char_u	*p;
     int		bri_shift = 0;
@@ -882,7 +886,11 @@
     int		bri_list = 0;
     int		bri_vcol = 0;
 
-    p = wp->w_p_briopt;
+    if (briopt != NULL)
+	p = briopt;
+    else
+	p = wp->w_p_briopt;
+
     while (*p != NUL)
     {
 	// Note: Keep this in sync with p_briopt_values
@@ -918,6 +926,9 @@
 	    ++p;
     }
 
+    if (wp == NULL)
+	return OK;
+
     wp->w_briopt_shift = bri_shift;
     wp->w_briopt_min   = bri_min;
     wp->w_briopt_sbr   = bri_sbr;