lib: Remove message document directly after removing the last file name.

Previously, notmuch_database_remove_message would remove the message
file name, sync the change to the message document, re-find the
message document, and then delete it if there were no more file names.
An interruption after sync'ing would result in a file-name-less,
permanently un-removable zombie message that would produce errors and
odd results in searches.  We could wrap this in an atomic section, but
it's much simpler to eliminate the round-about approach and just
delete the message document instead of sync'ing it if we removed the
last filename.

lib/database.cc

@@ -1747,7 +1747,6 @@ notmuch_status_t
 notmuch_database_remove_message (notmuch_database_t *notmuch,
 				 const char *filename)
 {
-    Xapian::WritableDatabase *db;
     void *local;
     const char *prefix = _find_prefix ("file-direntry");
     char *direntry, *term;
@@ -1761,8 +1760,6 @@ notmuch_database_remove_message (notmuch_database_t *notmuch,
 
     local = talloc_new (notmuch);
 
-    db = static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db);
-
     try {
 
 	status = _notmuch_database_filename_to_direntry (local, notmuch,
@@ -1785,23 +1782,11 @@ notmuch_database_remove_message (notmuch_database_t *notmuch,
 		return COERCE_STATUS (private_status,
 				      "Inconsistent document ID in datbase.");
 
-	    _notmuch_message_remove_filename (message, filename);
+	    status = _notmuch_message_remove_filename (message, filename);
+	    if (status == NOTMUCH_STATUS_SUCCESS)
+		_notmuch_message_delete (message);
+	    else if (status == NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID)
 		_notmuch_message_sync (message);
-
-	    /* Take care to find document after sync'ing filename removal. */
-	    document = find_document_for_doc_id (notmuch, *i);
-	    j = document.termlist_begin ();
-	    j.skip_to (prefix);
-
-	    /* Was this the last file-direntry in the message? */
-	    if (j == document.termlist_end () ||
-		strncmp ((*j).c_str (), prefix, strlen (prefix)))
-	    {
-		db->delete_document (document.get_docid ());
-		status = NOTMUCH_STATUS_SUCCESS;
-	    } else {
-		status = NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID;
-	    }
 	}
     } catch (const Xapian::Error &error) {
 	fprintf (stderr, "Error: A Xapian exception occurred removing message: %s\n",

lib/message.cc

@@ -822,6 +822,22 @@ _notmuch_message_sync (notmuch_message_t *message)
     db->replace_document (message->doc_id, message->doc);
 }
 
+/* Delete a message document from the database. */
+notmuch_status_t
+_notmuch_message_delete (notmuch_message_t *message)
+{
+    notmuch_status_t status;
+    Xapian::WritableDatabase *db;
+
+    status = _notmuch_database_ensure_writable (message->notmuch);
+    if (status)
+	return status;
+
+    db = static_cast <Xapian::WritableDatabase *> (message->notmuch->xapian_db);
+    db->delete_document (message->doc_id);
+    return NOTMUCH_STATUS_SUCCESS;
+}
+
 /* Ensure that 'message' is not holding any file object open. Future
  * calls to various functions will still automatically open the
  * message file as needed.

lib/notmuch-private.h

@@ -293,6 +293,9 @@ _notmuch_message_set_date (notmuch_message_t *message,
 void
 _notmuch_message_sync (notmuch_message_t *message);
 
+notmuch_status_t
+_notmuch_message_delete (notmuch_message_t *message);
+
 void
 _notmuch_message_close (notmuch_message_t *message);