[glib] gdatetime: Add g_date_time_get_timezone() accessor

[Philip Withnall <pwithnall src gnome org>]

commit 9ddd17d304642cd42f5e6a76af5cdadb46399ad0
Author: Philip Withnall <withnall endlessm com>
Date:   Wed Apr 11 15:58:23 2018 +0100

    gdatetime: Add g_date_time_get_timezone() accessor
    
    This is a trivial method to get the GTimeZone for the GDateTime.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=795165

 docs/reference/glib/glib-sections.txt |  1 +
 glib/gdatetime.c                      | 18 ++++++++++++++++++
 glib/gdatetime.h                      |  2 ++
 3 files changed, 21 insertions(+)
---
diff --git a/docs/reference/glib/glib-sections.txt b/docs/reference/glib/glib-sections.txt
index 2832983ee..58245049d 100644
--- a/docs/reference/glib/glib-sections.txt
+++ b/docs/reference/glib/glib-sections.txt
@@ -1743,6 +1743,7 @@ g_date_time_to_timeval
 
 <SUBSECTION>
 g_date_time_get_utc_offset
+g_date_time_get_timezone
 g_date_time_get_timezone_abbreviation
 g_date_time_is_daylight_savings
 
diff --git a/glib/gdatetime.c b/glib/gdatetime.c
index ba8503813..0ec01a31e 100644
--- a/glib/gdatetime.c
+++ b/glib/gdatetime.c
@@ -2566,6 +2566,24 @@ g_date_time_get_utc_offset (GDateTime *datetime)
   return (gint64) offset * USEC_PER_SECOND;
 }
 
+/**
+ * g_date_time_get_timezone:
+ * @datetime: a #GDateTime
+ *
+ * Get the time zone for this @datetime.
+ *
+ * Returns: (transfer none): the time zone
+ * Since: 2.58
+ */
+GTimeZone *
+g_date_time_get_timezone (GDateTime *datetime)
+{
+  g_return_val_if_fail (datetime != NULL, NULL);
+
+  g_assert (datetime->tz != NULL);
+  return datetime->tz;
+}
+
 /**
  * g_date_time_get_timezone_abbreviation:
  * @datetime: a #GDateTime
diff --git a/glib/gdatetime.h b/glib/gdatetime.h
index 025e452a2..65f9965ac 100644
--- a/glib/gdatetime.h
+++ b/glib/gdatetime.h
@@ -244,6 +244,8 @@ gboolean                g_date_time_to_timeval                          (GDateTi
 
 GLIB_AVAILABLE_IN_ALL
 GTimeSpan               g_date_time_get_utc_offset                      (GDateTime      *datetime);
+GLIB_AVAILABLE_IN_2_58
+GTimeZone *             g_date_time_get_timezone                        (GDateTime      *datetime);
 GLIB_AVAILABLE_IN_ALL
 const gchar *           g_date_time_get_timezone_abbreviation           (GDateTime      *datetime);
 GLIB_AVAILABLE_IN_ALL