[glib: 5/7] gchecksum: Add missing (transfer) and (nullable) return annotations

[Sebastian Dröge <sdroege src gnome org>]

commit 3fef04947288c65749ab2f1b8d3ece2357778a20
Author: Philip Withnall <pwithnall endlessos org>
Date:   Fri Dec 11 23:20:56 2020 +0000

    gchecksum: Add missing (transfer) and (nullable) return annotations
    
    This commit only looks at the `Returns:` lines in the documentation, and
    has examined all of them in the file. Function arguments have not been
    checked.
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>
    
    Helps: #2227

 glib/gchecksum.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)
---
diff --git a/glib/gchecksum.c b/glib/gchecksum.c
index f8a3f9ab8..f5ef9a443 100644
--- a/glib/gchecksum.c
+++ b/glib/gchecksum.c
@@ -1461,7 +1461,7 @@ g_checksum_type_get_length (GChecksumType checksum_type)
  * will be closed and it won't be possible to call g_checksum_update()
  * on it anymore.
  *
- * Returns: (transfer full): the newly created #GChecksum, or %NULL.
+ * Returns: (transfer full) (nullable): the newly created #GChecksum, or %NULL.
  *   Use g_checksum_free() to free the memory allocated by it.
  *
  * Since: 2.16
@@ -1529,8 +1529,8 @@ g_checksum_reset (GChecksum *checksum)
  * g_checksum_get_string() or g_checksum_get_digest(), the copied
  * checksum will be closed as well.
  *
- * Returns: the copy of the passed #GChecksum. Use g_checksum_free()
- *   when finished using it.
+ * Returns: (transfer full): the copy of the passed #GChecksum. Use
+ *   g_checksum_free() when finished using it.
  *
  * Since: 2.16
  */
@@ -1775,8 +1775,10 @@ g_checksum_get_digest (GChecksum  *checksum,
  *
  * The hexadecimal string returned will be in lower case.
  *
- * Returns: the digest of the binary data as a string in hexadecimal.
- *   The returned string should be freed with g_free() when done using it.
+ * Returns: (transfer full) (nullable): the digest of the binary data as a
+ *   string in hexadecimal, or %NULL if g_checksum_new() fails for
+ *   @checksum_type. The returned string should be freed with g_free() when
+ *   done using it.
  *
  * Since: 2.16
  */
@@ -1812,7 +1814,8 @@ g_compute_checksum_for_data (GChecksumType  checksum_type,
  *
  * The hexadecimal string returned will be in lower case.
  *
- * Returns: the checksum as a hexadecimal string. The returned string
+ * Returns: (transfer full) (nullable): the checksum as a hexadecimal string,
+ *   or %NULL if g_checksum_new() fails for @checksum_type. The returned string
  *   should be freed with g_free() when done using it.
  *
  * Since: 2.16
@@ -1842,8 +1845,10 @@ g_compute_checksum_for_string (GChecksumType  checksum_type,
  *
  * The hexadecimal string returned will be in lower case.
  *
- * Returns: the digest of the binary data as a string in hexadecimal.
- *   The returned string should be freed with g_free() when done using it.
+ * Returns: (transfer full) (nullable): the digest of the binary data as a
+ *   string in hexadecimal, or %NULL if g_checksum_new() fails for
+ *   @checksum_type. The returned string should be freed with g_free() when
+ *   done using it.
  *
  * Since: 2.34
  */