tag: added function tag_merge()

tag_merges() merges the data from two tag objects into one.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/tag.h b/src/tag.h
index c1c7d7e9..7c7abf50 100644
--- a/src/tag.h
+++ b/src/tag.h
@@ -90,6 +90,15 @@ static inline void tag_add_item(struct tag *tag, enum tag_type itemType,
 struct tag *tag_dup(const struct tag *tag);
 
 /**
+ * Merges the data from two tags.  If both tags share data for the
+ * same tag_type, only data from "add" is used.
+ *
+ * @return a newly allocated tag, which must be freed with tag_free()
+ */
+struct tag *
+tag_merge(const struct tag *base, const struct tag *add);
+
+/**
  * Returns true if the tag contains no items.  This ignores the "time"
  * attribute.
  */