epub: validate epub content before parsing

Check that the content file exists before attempting to parse it, and
handle failures in document title extraction gracefully.

1 files changed, 20 insertions, 3 deletions

diff --git a/backend/epub/epub-document.c b/backend/epub/epub-document.c
index 4aefb336..91e33faa 100644
--- a/backend/epub/epub-document.c
+++ b/backend/epub/epub-document.c
@@ -1600,13 +1600,17 @@ epub_document_toggle_night_mode(EvDocument *document,gboolean night)
 static gchar*
 epub_document_set_document_title(gchar *containeruri)
 {
-    open_xml_document(containeruri);
-    gchar *doctitle;
+    if (open_xml_document(containeruri) == FALSE)
+        return NULL;
+
+    gchar *doctitle = NULL;
     set_xml_root_node(NULL);
 
     xmlNodePtr title = xml_get_pointer_to_node((xmlChar*)"title",NULL,NULL);
 
-    doctitle = (gchar*)xml_get_data_from_node(title, XML_KEYWORD, NULL);
+    if (title != NULL)
+        doctitle = (gchar*)xml_get_data_from_node(title, XML_KEYWORD, NULL);
+
     xml_free_doc();
 
     return doctitle;
@@ -1758,6 +1762,19 @@ epub_document_load (EvDocument* document,
         return FALSE;
     }
 
+    gchar *contentOpfPath = g_filename_from_uri(contentOpfUri,NULL,NULL);
+    if (contentOpfPath == NULL || !g_file_test(contentOpfPath, G_FILE_TEST_IS_REGULAR))
+    {
+        g_free (contentOpfPath);
+        g_free (contentOpfUri);
+        g_set_error_literal(error,
+                            EV_DOCUMENT_ERROR,
+                            EV_DOCUMENT_ERROR_INVALID,
+                            _("could not find epub content"));
+        return FALSE;
+    }
+    g_free (contentOpfPath);
+
     epub_document->docTitle = epub_document_set_document_title(contentOpfUri);
     epub_document->index = setup_document_index(epub_document,contentOpfUri);