[PATCH v6 06/14] reindex: drop all properties named with prefix "index."

[Daniel Kahn Gillmor]

This allows us to create new properties that will be automatically set
during indexing, and cleared during re-indexing, just by choice of
property name.
---
 doc/man7/notmuch-properties.rst | 6 ++++++
 lib/message.cc                  | 6 ++++++
 lib/notmuch.h                   | 6 ++++++
 3 files changed, 18 insertions(+)

diff --git a/doc/man7/notmuch-properties.rst b/doc/man7/notmuch-properties.rst
index ffaa2418..2ab4f3f4 100644
--- a/doc/man7/notmuch-properties.rst
+++ b/doc/man7/notmuch-properties.rst
@@ -41,6 +41,12 @@ Extensions to notmuch which make use of properties are encouraged to
 report the specific properties used to the upstream notmuch project,
 as a way of avoiding collisions in the property namespace.
 
+CONVENTIONS
+===========
+
+Any property with a key that starts with "index." will be removed (and
+possibly re-set) upon reindexing (see **notmuch-reindex(1)**).
+
 SEE ALSO
 ========
 
diff --git a/lib/message.cc b/lib/message.cc
index 4ab0ed26..77bb6c76 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -1999,6 +1999,12 @@ notmuch_message_reindex (notmuch_message_t *message,
 	goto DONE;
     }
 
+    ret = notmuch_message_remove_all_properties_with_prefix (message, "index.");
+    if (ret) {
+	INTERNAL_ERROR ("failed to remove index.* properties");
+	goto DONE;
+    }
+
     /* re-add the filenames with the associated indexopts */
     for (; notmuch_filenames_valid (orig_filenames);
 	 notmuch_filenames_move_to_next (orig_filenames)) {
diff --git a/lib/notmuch.h b/lib/notmuch.h
index 817f357f..01191a41 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -1765,6 +1765,12 @@ notmuch_message_destroy (notmuch_message_t *message);
  * add or delete values for, as other subsystems or extensions may
  * depend on these properties.
  *
+ * Notmuch has some conventions about how certain properties are
+ * treated.  Those conventions include:
+ *
+ * - properties whose name begins with "index." are cleared (and
+ *   possibly re-set) upon reindexing.
+ *
  */
 /**@{*/
 /**
-- 
2.14.2