[pango/line-breaker] pango-lines: more cornercases

[Matthias Clasen <matthiasc src gnome org>]

commit 615bae911865ee4bfebcdc6d9526ee856dc2ba7a
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Jan 24 13:55:07 2022 -0500

    pango-lines: more cornercases

 pango/pango-lines.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)
---
diff --git a/pango/pango-lines.c b/pango/pango-lines.c
index de86735c..bf28f9e9 100644
--- a/pango/pango-lines.c
+++ b/pango/pango-lines.c
@@ -1000,7 +1000,7 @@ pango_lines_get_caret_pos (PangoLines      *lines,
  *   was at the trailing edge.
  * @direction: direction to move cursor. A negative
  *   value indicates motion to the left
- * @new_line: `PangoLayoutLine` wrt to which @new_idx is interpreted
+ * @new_line: (nullable): `PangoLayoutLine` wrt to which @new_idx is interpreted
  * @new_idx: (out): location to store the new cursor byte index
  *   A value of -1 indicates that the cursor has been moved off the
  *   beginning of the layout. A value of %G_MAXINT indicates that
@@ -1052,7 +1052,6 @@ pango_lines_move_cursor (PangoLines       *lines,
   g_return_if_fail (PANGO_IS_LINES (lines));
   g_return_if_fail (idx >= 0);
   g_return_if_fail (trailing >= 0);
-  g_return_if_fail (new_line != NULL);
   g_return_if_fail (new_idx != NULL);
   g_return_if_fail (new_trailing != NULL);
 
@@ -1127,7 +1126,8 @@ pango_lines_move_cursor (PangoLines       *lines,
           prev_line = pango_lines_get_line (lines, line_no - 1, NULL, NULL);
           if (!prev_line)
             {
-              *new_line = NULL;
+              if (new_line)
+                *new_line = NULL;
               *new_idx = -1;
               *new_trailing = 0;
               g_array_unref (cursors);
@@ -1145,7 +1145,8 @@ pango_lines_move_cursor (PangoLines       *lines,
           next_line = pango_lines_get_line (lines, line_no + 1, NULL, NULL);
           if (!next_line)
             {
-              *new_line = NULL;
+              if (new_line)
+                *new_line = NULL;
               *new_idx = G_MAXINT;
               *new_trailing = 0;
               g_array_unref (cursors);
@@ -1202,7 +1203,8 @@ pango_lines_move_cursor (PangoLines       *lines,
       while (log_pos > start_offset && !line->data->log_attrs[log_pos].is_cursor_position);
     }
 
-  *new_line = line;
+  if (new_line)
+    *new_line = line;
 
   g_array_unref (cursors);
 }