[PATCH 11/12] lib/message: check message data_map for header

[David Bremner]

The will allow the indexing process to override the values in the
files. This is potentially useful for encrypted headers, or in
resolving duplicate files for the same message(-id).
---
 lib/message.cc | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/message.cc b/lib/message.cc
index f59f0a5c..c3c71fd4 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -552,11 +552,30 @@ _notmuch_message_get_header_from_xapian (notmuch_message_t *message,
     return NULL;
 }
 
+static const char *
+_notmuch_message_get_header_from_data (notmuch_message_t *message, const char *header) {
+    _notmuch_message_ensure_data_map (message);
+
+    if (! (message->notmuch->features & NOTMUCH_FEATURE_MESSAGE_DATA))
+	return NULL;
+
+    const char *key = talloc_asprintf (message->data_map, "header.%s", header);
+
+    if (! key)
+	return NULL;
+
+    return _notmuch_string_map_get (message->data_map, key);
+}
+
 const char *
 notmuch_message_get_header (notmuch_message_t *message, const char *header)
 {
-    Xapian::valueno slot = Xapian::BAD_VALUENO;
+    /* Have we explicitly chosen / set this header */
+    const char *value = _notmuch_message_get_header_from_data (message, header);
+    if (value)
+	return value;
 
+    Xapian::valueno slot = Xapian::BAD_VALUENO;
     /* Fetch header from the appropriate xapian value field if
      * available */
     if (strcasecmp (header, "from") == 0)
-- 
2.17.1