[niepce: 26/29] engine: Set an empty string is property return nullptr

[Hubert Figuière <hub src gnome org>]

commit 65bde773bf2a21a4c3ac13baffe947b86eec37cd
Author: Hubert Figuière <hub figuiere net>
Date:   Sat Sep 16 23:38:59 2017 -0400

    engine: Set an empty string is property return nullptr

 src/engine/db/libmetadata.cpp |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/engine/db/libmetadata.cpp b/src/engine/db/libmetadata.cpp
index 9075ae1..0dedae8 100644
--- a/src/engine/db/libmetadata.cpp
+++ b/src/engine/db/libmetadata.cpp
@@ -122,6 +122,9 @@ void libmetadata_to_properties(const LibMetadata *meta,
                     props.set_value_for_property(prop_id,
                                                  fwk::PropertyValue(str));
                     rust_cstring_delete(str);
+                } else {
+                    props.set_value_for_property(prop_id,
+                                                 fwk::PropertyValue(""));
                 }
                 break;
             }