[gnome-epub-thumbnailer] epub: Add a warning when reading empty files

[Bastien Nocera <hadess src gnome org>]

commit d2f1236c69c190299afd6d020a4b97158ebee962
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Sep 2 03:07:33 2013 +0200

    epub: Add a warning when reading empty files

 gnome-epub-thumbnailer.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gnome-epub-thumbnailer.c b/gnome-epub-thumbnailer.c
index 20c81d9..13cc2d9 100644
--- a/gnome-epub-thumbnailer.c
+++ b/gnome-epub-thumbnailer.c
@@ -89,6 +89,10 @@ file_get_zipped_contents (const char   *filename,
                        read = archive_read_data (a, buf, size);
                        if (read <= 0) {
                                g_free (buf);
+                               if (read < 0)
+                                       g_warning ("Fatal error reading '%s' in archive: %s", name, 
archive_error_string (a));
+                               else
+                                       g_warning ("Read an empty file from the archive");
                        } else {
                                ret = buf;
                                *length = size;