[glib: 2/6] gsettings: Clarify ownership transfer in a few places

[Simon McVittie <smcv src gnome org>]

commit f829b65e518a82bd8cb350bb576bcfd6186c3064
Author: Philip Withnall <withnall endlessm com>
Date:   Wed Jan 23 15:15:53 2019 +0000

    gsettings: Clarify ownership transfer in a few places
    
    I was trying to debug some memory leaks in the gsettings test.
    Eventually, it seems that actually they’re caused by the
    GMemorySettingsBackend being cached by GIOModule — so this commit makes
    no functional changes. It should make the code and documentation a bit
    clearer though.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>

 gio/gsettings.c        | 8 +++++---
 gio/gsettingsbackend.c | 2 ++
 gio/gsettingsschema.c  | 2 ++
 3 files changed, 9 insertions(+), 3 deletions(-)
---
diff --git a/gio/gsettings.c b/gio/gsettings.c
index 2934f2b4b..dd8f94485 100644
--- a/gio/gsettings.c
+++ b/gio/gsettings.c
@@ -1137,6 +1137,8 @@ g_settings_new_full (GSettingsSchema  *schema,
 }
 
 /* Internal read/write utilities {{{1 */
+
+/* @value will be sunk */
 static gboolean
 g_settings_write_to_backend (GSettings          *settings,
                              GSettingsSchemaKey *key,
@@ -1417,7 +1419,7 @@ g_settings_set_enum (GSettings   *settings,
       return FALSE;
     }
 
-  success = g_settings_write_to_backend (settings, &skey, variant);
+  success = g_settings_write_to_backend (settings, &skey, g_steal_pointer (&variant));
   g_settings_schema_key_clear (&skey);
 
   return success;
@@ -1528,7 +1530,7 @@ g_settings_set_flags (GSettings   *settings,
       return FALSE;
     }
 
-  success = g_settings_write_to_backend (settings, &skey, variant);
+  success = g_settings_write_to_backend (settings, &skey, g_steal_pointer (&variant));
   g_settings_schema_key_clear (&skey);
 
   return success;
@@ -1672,7 +1674,7 @@ g_settings_set (GSettings   *settings,
   value = g_variant_new_va (format, NULL, &ap);
   va_end (ap);
 
-  return g_settings_set_value (settings, key, value);
+  return g_settings_set_value (settings, key, g_steal_pointer (&value));
 }
 
 /**
diff --git a/gio/gsettingsbackend.c b/gio/gsettingsbackend.c
index edc4ff4d3..ca9b908a5 100644
--- a/gio/gsettingsbackend.c
+++ b/gio/gsettingsbackend.c
@@ -777,6 +777,8 @@ g_settings_backend_read_user_value (GSettingsBackend   *backend,
  * to indicate that the affected keys have suddenly "changed back" to their
  * old values.
  *
+ * If @value has a floating reference, it will be sunk.
+ *
  * Returns: %TRUE if the write succeeded, %FALSE if the key was not writable
  */
 gboolean
diff --git a/gio/gsettingsschema.c b/gio/gsettingsschema.c
index 38c9d78b9..60b3fe0b3 100644
--- a/gio/gsettingsschema.c
+++ b/gio/gsettingsschema.c
@@ -1472,6 +1472,7 @@ g_settings_schema_key_to_enum (GSettingsSchemaKey *key,
   return result;
 }
 
+/* Returns a new floating #GVariant. */
 GVariant *
 g_settings_schema_key_from_enum (GSettingsSchemaKey *key,
                                  gint                value)
@@ -1511,6 +1512,7 @@ g_settings_schema_key_to_flags (GSettingsSchemaKey *key,
   return result;
 }
 
+/* Returns a new floating #GVariant. */
 GVariant *
 g_settings_schema_key_from_flags (GSettingsSchemaKey *key,
                                   guint               value)