[PATCH v2 5/7] lib: return NOTMUCH_STATUS_OPERATION_INVALIDATED where appropriate

[David Bremner]

I have applied the first 4 patches in the series to master.

>  	notmuch->exception_reported = true;
> -	ret = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
> +	ret = _notmuch_xapian_error(error);

devel/STYLE says there needs to be a space after _notmuch_xapian_error
here. uncrustify -c devel/uncrustify.cfg can (mostly) automate this.

> --- a/lib/message.cc
> +++ b/lib/message.cc
> @@ -297,7 +297,7 @@ _notmuch_message_create_for_message_id (notmuch_database_t *notmuch,
>  			       "A Xapian exception occurred creating message: %s\n",
>  			       error.get_msg ().c_str ());
>  	notmuch->exception_reported = true;
> -	*status_ret = NOTMUCH_PRIVATE_STATUS_XAPIAN_EXCEPTION;
> +	*status_ret = _notmuch_xapian_errorp(error);

please err on the side verbosity when adding new (private) API functions.

> +static inline notmuch_private_status_t
> +_notmuch_xapian_errorp (const Xapian::Error &error)
> +{
> +    const char *type = error.get_type();
> +	return (! strcmp (type, "DatabaseModifiedError")) ?
> +	    NOTMUCH_PRIVATE_STATUS_OPERATION_INVALIDATED : NOTMUCH_PRIVATE_STATUS_XAPIAN_EXCEPTION;
> +}

My first reaction to using strcmp here is ugh, but I guess that's the
intended method of introspection. I have CC'ed xapian-users, in case
someone there wants to comment. Naively, it seems like a case where
typeid would be useful, but I am not enough of a C++ expert to
understand why Xapian doesn't do that.