[glib] gio: Mention the ALL_METADATA flag in g_file_copy()

[Emanuele Aina <emaaa src gnome org>]

commit 79e4d4c6be616277d7d6ba2f830852967c42f6e3
Author: Emanuele Aina <emanuele aina collabora com>
Date:   Wed Jun 21 15:45:07 2017 +0200

    gio: Mention the ALL_METADATA flag in g_file_copy()
    
    The g_file_copy() documentation didn't mention if
    G_FILE_COPY_ALL_METADATA was applicable or not, and users were led to
    call g_file_copy_attributes() to specify it after the g_file_copy()
    call, unless they checked the source (been there, done that).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=784037

 gio/gfile.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gio/gfile.c b/gio/gfile.c
index 212d3e0..dd518df 100644
--- a/gio/gfile.c
+++ b/gio/gfile.c
@@ -3299,6 +3299,10 @@ file_copy_fallback (GFile                  *source,
  * will be copied as symlinks, otherwise the target of the
  * @source symlink will be copied.
  *
+ * If the flag #G_FILE_COPY_ALL_METADATA is specified then all the metadata
+ * that is possible to copy is copied, not just the default subset (which,
+ * for instance, does not include the owner, see #GFileInfo).
+ *
  * If @cancellable is not %NULL, then the operation can be cancelled by
  * triggering the cancellable object from another thread. If the operation
  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.