[evince/BUG_fix_annotation_warning] fix warning on documents lacking annotations interface

[Nelson Ben <nbenitez src gnome org>]

commit 6464bdb140be965042c478595732f4b7743dd611
Author: Nelson Benítez León <nbenitezl gmail com>
Date:   Wed Jun 17 12:57:34 2020 -0400

    fix warning on documents lacking annotations interface

 libview/ev-view.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/libview/ev-view.c b/libview/ev-view.c
index b805ea6a..046cd6c5 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -3355,6 +3355,9 @@ get_annotation_mapping_at_location (EvView *view,
        EvMapping *best;
        GList *list;
 
+       if (!EV_IS_DOCUMENT_ANNOTATIONS (view->document))
+               return NULL;
+
        doc_annots = EV_DOCUMENT_ANNOTATIONS (view->document);
 
        if (!doc_annots)