[glib] gvalue: Improve _unset() documentation

[Nicolas Dufresne <nicolasd src gnome org>]

commit 3c0d38d68b78a6ea9e6ca82012f011075a625a2b
Author: Nicolas Dufresne <nicolas dufresne collabora co uk>
Date:   Tue Sep 29 08:30:21 2015 -0400

    gvalue: Improve _unset() documentation
    
    g_value_unset() only works with initialized value and will assert
    if the GValue is zero-filled (or initialized with G_VALUE_INIT). Document
    this behaviour and refer to g_value_clear() for a method that work on
    both initialized and zero-filled GValue.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=755766

 gobject/gvalue.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/gobject/gvalue.c b/gobject/gvalue.c
index c91584e..32ad867 100644
--- a/gobject/gvalue.c
+++ b/gobject/gvalue.c
@@ -257,7 +257,9 @@ g_value_reset (GValue *value)
  * Clears the current value in @value and "unsets" the type,
  * this releases all resources associated with this GValue.
  * An unset value is the same as an uninitialized (zero-filled)
- * #GValue structure.
+ * #GValue structure. Note that you cannot call this method on
+ * uninitialized structure, for that, g_value_clear() method can
+ * be used.
  */
 void
 g_value_unset (GValue *value)