[goffice] Revert previous and really fix.

[Jean Bréfort <jbrefort src gnome org>]

commit c40bdab5a058e82d65f489eea44494a843e374f4
Author: Jean Brefort <jean brefort normalesup org>
Date:   Wed May 6 20:23:09 2015 +0200

    Revert previous and really fix.

 ChangeLog                 |    4 ++--
 goffice/utils/go-image.c  |    5 +----
 goffice/utils/go-pixbuf.c |    2 +-
 3 files changed, 4 insertions(+), 7 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index a9b81b7..d022a3e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,7 +1,7 @@
 2015-05-06  Jean Brefort  <jean brefort normalesup org>
 
-       * goffice/utils/go-image.c (go_image_save): save original pixbuf data.
-       [see #748493, comments 13 and 14] 
+       * goffice/utils/go-pixbuf.c (go_pixbuf_save): don't save when no data is
+       available [see #748493, comments 13 to 16] 
 
 2015-05-04  Morten Welinder  <terra gnome org>
 
diff --git a/goffice/utils/go-image.c b/goffice/utils/go-image.c
index 7a9cb2e..d79eea8 100644
--- a/goffice/utils/go-image.c
+++ b/goffice/utils/go-image.c
@@ -770,10 +770,7 @@ go_image_save (GOImage *image, GsfXMLOut *output)
        gsf_xml_out_add_cstr (output, "type", G_OBJECT_TYPE_NAME (image));
        gsf_xml_out_add_int (output, "width", image->width);
        gsf_xml_out_add_int (output, "height", image->height);
-       if (image->data != NULL && image->data_length > 0)
-               gsf_xml_out_add_base64 (output, NULL, image->data, image->data_length);
-       else /* should this still happen? */
-               ((GOImageClass *) G_OBJECT_GET_CLASS (image))->save (image, output);
+       ((GOImageClass *) G_OBJECT_GET_CLASS (image))->save (image, output);
        gsf_xml_out_end_element (output);
 }
 
diff --git a/goffice/utils/go-pixbuf.c b/goffice/utils/go-pixbuf.c
index 6d2e4c7..e46562b 100644
--- a/goffice/utils/go-pixbuf.c
+++ b/goffice/utils/go-pixbuf.c
@@ -85,7 +85,7 @@ static void
 go_pixbuf_save (GOImage *image, GsfXMLOut *output)
 {
        GOPixbuf *pixbuf;
-       g_return_if_fail (GO_IS_PIXBUF (image));
+       g_return_if_fail (GO_IS_PIXBUF (image) && image->data != NULL);
        pixbuf = GO_PIXBUF (image);
        if (pixbuf->type == NULL) {
                pixbuf->type = g_strdup ("png");