[glib] GVariant: add new g_variant_new_take_string() API

[Ryan Lortie <ryanl src gnome org>]

commit dbb65b54651a88b9691b156bf19b53fbe4a4bd5a
Author: Ryan Lortie <desrt desrt ca>
Date:   Sat Apr 20 11:44:53 2013 -0400

    GVariant: add new g_variant_new_take_string() API
    
    Lots of people have variously asked for APIs like
    g_variant_new_string_printf() in order to avoid having to use
    g_strdup_printf(), create a GVariant using g_variant_new_string(), then
    free the temporary string.
    
    Instead of supporting that, plus a million other potential cases,
    introduce g_variant_new_take_string() as a compromise.
    
    It's not possible to write:
    
     v = g_variant_new_take_string (g_strdup_printf (....));
    
    to get the desired result and avoid the extra copies.  In addition, it
    works with many other functions.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=698455

 docs/reference/glib/glib-sections.txt |  1 +
 glib/gvariant.c                       | 36 +++++++++++++++++++++++++++++++++++
 glib/gvariant.h                       |  2 ++
 3 files changed, 39 insertions(+)
---
diff --git a/docs/reference/glib/glib-sections.txt b/docs/reference/glib/glib-sections.txt
index 4153a29..788af8d 100644
--- a/docs/reference/glib/glib-sections.txt
+++ b/docs/reference/glib/glib-sections.txt
@@ -3108,6 +3108,7 @@ g_variant_new_uint64
 g_variant_new_handle
 g_variant_new_double
 g_variant_new_string
+g_variant_new_take_string
 g_variant_new_object_path
 g_variant_is_object_path
 g_variant_new_signature
diff --git a/glib/gvariant.c b/glib/gvariant.c
index 163782d..8c8f66c 100644
--- a/glib/gvariant.c
+++ b/glib/gvariant.c
@@ -1274,6 +1274,42 @@ g_variant_new_string (const gchar *string)
 }
 
 /**
+ * g_variant_new_take_string: (skip)
+ * @string: a normal utf8 nul-terminated string
+ *
+ * Creates a string #GVariant with the contents of @string.
+ *
+ * @string must be valid utf8.
+ *
+ * This function consumes @string.  g_free() will be called on @string
+ * when it is no longer required.
+ *
+ * You must not modify or access @string in any other way after passing
+ * it to this function.  It is even possible that @string is immediately
+ * freed.
+ *
+ * Returns: (transfer none): a floating reference to a new string
+ *   #GVariant instance
+ *
+ * Since: 2.38
+ **/
+GVariant *
+g_variant_new_take_string (gchar *string)
+{
+  GVariant *value;
+  GBytes *bytes;
+
+  g_return_val_if_fail (string != NULL, NULL);
+  g_return_val_if_fail (g_utf8_validate (string, -1, NULL), NULL);
+
+  bytes = g_bytes_new_take (string, strlen (string) + 1);
+  value = g_variant_new_from_bytes (G_VARIANT_TYPE_STRING, bytes, TRUE);
+  g_bytes_unref (bytes);
+
+  return value;
+}
+
+/**
  * g_variant_new_object_path:
  * @object_path: a normal C nul-terminated string
  *
diff --git a/glib/gvariant.h b/glib/gvariant.h
index 01b7b5e..7e9a823 100644
--- a/glib/gvariant.h
+++ b/glib/gvariant.h
@@ -101,6 +101,8 @@ GLIB_AVAILABLE_IN_ALL
 GVariant *                      g_variant_new_double                    (gdouble               value);
 GLIB_AVAILABLE_IN_ALL
 GVariant *                      g_variant_new_string                    (const gchar          *string);
+GLIB_AVAILABLE_IN_2_38
+GVariant *                      g_variant_new_take_string               (gchar                *string);
 GLIB_AVAILABLE_IN_ALL
 GVariant *                      g_variant_new_object_path               (const gchar          *object_path);
 GLIB_AVAILABLE_IN_ALL