[evince] comics: Add error reporting to comics_document_list()

[Bastien Nocera <hadess src gnome org>]

commit 2efa1318e2dbbd63a08319762c09db79b05545ff
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Jul 18 11:35:23 2017 +0200

    comics: Add error reporting to comics_document_list()
    
    So that we can know whether a NULL return value is due to an empty file
    or a broken file.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=784963

 backend/comics/comics-document.c |   45 ++++++++++++++++++++++++++-----------
 1 files changed, 31 insertions(+), 14 deletions(-)
---
diff --git a/backend/comics/comics-document.c b/backend/comics/comics-document.c
index acbdeb3..611d752 100644
--- a/backend/comics/comics-document.c
+++ b/backend/comics/comics-document.c
@@ -59,24 +59,42 @@ static GSList* get_supported_image_extensions (void);
 EV_BACKEND_REGISTER (ComicsDocument, comics_document)
 
 static char **
-comics_document_list (ComicsDocument *comics_document)
+comics_document_list (ComicsDocument  *comics_document,
+                     GError         **error)
 {
        char **ret = NULL;
        GPtrArray *array;
 
-       if (!ev_archive_open_filename (comics_document->archive, comics_document->archive_path, NULL))
+       if (!ev_archive_open_filename (comics_document->archive, comics_document->archive_path, error)) {
+               if (*error != NULL) {
+                       g_debug ("Fatal error handling archive: %s", (*error)->message);
+                       g_clear_error (error);
+               }
+
+               g_set_error_literal (error,
+                                    EV_DOCUMENT_ERROR,
+                                    EV_DOCUMENT_ERROR_INVALID,
+                                    _("File is corrupted"));
                goto out;
+       }
 
        array = g_ptr_array_new ();
 
        while (1) {
                const char *name;
-               GError *error = NULL;
 
-               if (!ev_archive_read_next_header (comics_document->archive, &error)) {
-                       if (error != NULL) {
-                               g_warning ("Fatal error handling archive: %s", error->message);
-                               g_error_free (error);
+               if (!ev_archive_read_next_header (comics_document->archive, error)) {
+                       if (*error != NULL) {
+                               g_debug ("Fatal error handling archive: %s", (*error)->message);
+                               g_clear_error (error);
+
+                               g_ptr_array_free (array, TRUE);
+
+                               g_set_error_literal (error,
+                                                    EV_DOCUMENT_ERROR,
+                                                    EV_DOCUMENT_ERROR_INVALID,
+                                                    _("File is corrupted"));
+                               goto out;
                        }
                        break;
                }
@@ -89,6 +107,10 @@ comics_document_list (ComicsDocument *comics_document)
 
        if (array->len == 0) {
                g_ptr_array_free (array, TRUE);
+               g_set_error_literal (error,
+                                    EV_DOCUMENT_ERROR,
+                                    EV_DOCUMENT_ERROR_INVALID,
+                                    _("No files in archive"));
        } else {
                g_ptr_array_add (array, NULL);
                ret = (char **) g_ptr_array_free (array, FALSE);
@@ -194,14 +216,9 @@ comics_document_load (EvDocument *document,
        g_free (mime_type);
 
        /* Get list of files in archive */
-       cb_files = comics_document_list (comics_document);
-       if (!cb_files) {
-               g_set_error_literal (error,
-                                     EV_DOCUMENT_ERROR,
-                                     EV_DOCUMENT_ERROR_INVALID,
-                                     _("File corrupted or no files in archive"));
+       cb_files = comics_document_list (comics_document, error);
+       if (!cb_files)
                return FALSE;
-       }
 
         comics_document->page_names = g_ptr_array_sized_new (64);