Re: [python] segfaults at Message.get_date

[Austin Clements <amdragon@mit.edu>]

On Sun, Jun 19, 2011 at 5:45 AM, Dmitry Kurochkin
<dmitry.kurochkin@gmail.com> wrote:
> Hi Sebastian, Patrick.
>
> On Sat, 18 Jun 2011 12:30:01 +0200, Sebastian Spaeth <Sebastian@SSpaeth.de> wrote:
>> On Fri, 17 Jun 2011 17:10:24 +0100, Patrick Totzke :
>> > #0  0x006eb87d in Xapian::Document::Internal::get_value(unsigned int) const () from /usr/lib/sse2/libxapian.so.22
>> > #1  0x006eb952 in Xapian::Document::get_value(unsigned int) const () from /usr/lib/sse2/libxapian.so.22
>> > #2  0x00523963 in notmuch_message_get_date () from /usr/local/lib/libnotmuch.so.1
>>
>> One question, what type is libnotmuch really returning here? The code:
>>
>>
>> time_t
>> notmuch_message_get_date (notmuch_message_t *message)
>> {   ...
>>     return Xapian::sortable_unserialise (value);
>> }
>>
>> But Xapian API says that sortable_unserialise() returns floating type "double"
>>
>> http://xapian.org/docs/apidoc/html/namespaceXapian.html#326fe2d6b0ee59ac9536f3960e8fd99b
>> "Convert a string encoded using sortable_serialise back to a floating
>> point number."
>>
>> But time_t is usually a (signed) long and not floating point. Obviously
>> things have worked just fine so far, but is libnotmuch really returning
>> the right type here? Sorry, I expose my total lack of basic C++ knowledge
>> here...
>>
>
> Converting double to time_t does not look good.  Notmuch converts
> between time_t and double both when setting and getting the date.  I
> guess it should work good in most cases at least.  Perhaps Carl knows
> better that it is safe.

A double will precisely represent integers up to 2^53, so this
conversion shouldn't be a problem until the year 285422109 or so.