[libgxps] gxps-images: clear the error before trying to load an image again

[Carlos Garcia Campos <carlosgc src gnome org>]

commit 672c65ea8cbd2bcfd82a6b6498a4f1eb9daf5ec5
Author: Carlos Garcia Campos <carlosgc gnome org>
Date:   Fri Dec 8 11:20:25 2017 +0100

    gxps-images: clear the error before trying to load an image again
    
    In gxps_images_get_image() we first try with the image file extension,
    and if that fails then we try guessing the content type. If the image
    load failed the first time, the GError might be filled already, so we
    need to clear it before passing it to create functions again.

 libgxps/gxps-images.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/libgxps/gxps-images.c b/libgxps/gxps-images.c
index 19cb1c0..4dcf9e2 100644
--- a/libgxps/gxps-images.c
+++ b/libgxps/gxps-images.c
@@ -925,6 +925,8 @@ gxps_images_get_image (GXPSArchive *zip,
        if (!image) {
                gchar *mime_type;
 
+                g_clear_error(error);
+
                mime_type = gxps_images_guess_content_type (zip, image_uri);
                if (g_strcmp0 (mime_type, "image/png") == 0) {
                        image = gxps_images_create_from_png (zip, image_uri, error);