1 files changed, 4 insertions, 3 deletions

diff --git a/src/dispnew.c b/src/dispnew.c
index 8abf5782a88..385ad98e21f 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -3578,12 +3578,11 @@ update_window (struct window *w, int force_p)
 
       rif->update_window_begin_hook (w);
       yb = window_text_bottom_y (w);
-
-      /* If window has a header line, update it before everything else.
-         Adjust y-positions of other rows by the header line height.  */
       row = desired_matrix->rows;
       end = row + desired_matrix->nrows - 1;
 
+      /* Take note of the header line, if there is one.  We will
+         update it below, after updating all of the window's lines.  */
       if (row->mode_line_p)
         {
           header_line_row = row;
@@ -3628,6 +3627,8 @@ update_window (struct window *w, int force_p)
 
       /* Update the rest of the lines.  */
       for (; row < end && (force_p || !input_pending); ++row)
+        /* scrolling_window resets the enabled_p flag of the rows it
+           reuses from current_matrix.  */
         if (row->enabled_p)
           {
             int vpos = MATRIX_ROW_VPOS (row, desired_matrix);