[glib: 1/4] garray: Fix (nullable) annotation on GArray.[prepend|insert]_vals()

[Philip Withnall <pwithnall src gnome org>]

commit 3eeec77800ab6019febe8fb73ec34533770752c5
Author: Philip Withnall <withnall endlessm com>
Date:   Wed May 9 15:34:39 2018 +0100

    garray: Fix (nullable) annotation on GArray.[prepend|insert]_vals()
    
    They do both accept NULL value arrays, but only if the number of
    elements in the value array is zero. Fix the annotations and mention
    this in the documentation.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=795975

 glib/garray.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)
---
diff --git a/glib/garray.c b/glib/garray.c
index 914eaee34..5207eccc3 100644
--- a/glib/garray.c
+++ b/glib/garray.c
@@ -439,11 +439,14 @@ g_array_append_vals (GArray       *farray,
 /**
  * g_array_prepend_vals:
  * @array: a #GArray
- * @data: (not nullable): a pointer to the elements to prepend to the start of the array
- * @len: the number of elements to prepend
+ * @data: (nullable): a pointer to the elements to prepend to the start of the array
+ * @len: the number of elements to prepend, which may be zero
  *
  * Adds @len elements onto the start of the array.
  *
+ * @data may be %NULL if (and only if) @len is zero. If @len is zero, this
+ * function is a no-op.
+ *
  * This operation is slower than g_array_append_vals() since the
  * existing elements in the array have to be moved to make space for
  * the new elements.
@@ -498,11 +501,14 @@ g_array_prepend_vals (GArray        *farray,
  * g_array_insert_vals:
  * @array: a #GArray
  * @index_: the index to place the elements at
- * @data: (not nullable): a pointer to the elements to insert
+ * @data: (nullable): a pointer to the elements to insert
  * @len: the number of elements to insert
  *
  * Inserts @len elements into a #GArray at the given index.
  *
+ * @data may be %NULL if (and only if) @len is zero. If @len is zero, this
+ * function is a no-op.
+ *
  * Returns: the #GArray
  */
 /**