+ * If 'database_path' is non-NULL, but does not appear to be a Xapian
+ * database, check for a directory '.notmuch/xapian' below
+ * 'database_path' (this is the behavior of
+ * notmuch_database_open_verbose pre-0.32).
+ *
+ * @endparblock
+ * @param[in] mode
+ * @parblock
+ * Mode to open database. Use one of #NOTMUCH_DATABASE_MODE_READ_WRITE
+ * or #NOTMUCH_DATABASE_MODE_READ_ONLY
+ *
+ * @endparblock
+ * @param[in] config_path
+ * @parblock
+ * Path to config file.
+ *
+ * Config file is key-value, with mandatory sections. See
+ * <em>notmuch-config(5)</em> for more information. The key-value pair
+ * overrides the corresponding configuration data stored in the
+ * database (see <em>notmuch_database_get_config</em>)
+ *
+ * If <em>config_path</em> is NULL use the path specified
+ *
+ * - in environment variable <em>NOTMUCH_CONFIG</em>, if non-empty
+ *
+ * - by <em>XDG_CONFIG_HOME</em>/notmuch/ where
+ * XDG_CONFIG_HOME defaults to "$HOME/.config".
+ *
+ * - by $HOME/.notmuch-config
+ *
+ * If <em>config_path</em> is "" (empty string) then do not
+ * open any configuration file.
+ * @endparblock
+ * @param[in] profile:
+ * @parblock
+ * Name of profile (configuration/database variant).
+ *
+ * If non-NULL, append to the directory / file path determined for
+ * <em>config_path</em> and <em>database_path</em>.
+ *
+ * If NULL then use
+ * - environment variable NOTMUCH_PROFILE if defined,
+ * - otherwise "default" for directories and "" (empty string) for paths.
+ *
+ * @endparblock
+ * @param[out] database
+ * @parblock
+ * Pointer to database object. May not be NULL.