KPixmapCache in kdelibs4support uses QDateTime in mmap'ed struct

[Alex Merry]

On 2015-11-03 00:56, Michael Pyne wrote:
> On Tue, November 3, 2015 00:40:58 Albert Astals Cid wrote:
>> Someone went a bit too far in the "port away from time_t to QDateTime" 
>> and
>> changed the timestamp member of the KPixmapCacheIndexHeader struct.
>> 
>> According to mpyne and thiago this is a big no-no.
> 
> The reason it's a big no-no is because KPixmapCacheIndexHeader is meant 
> to be
> held and used from mmap()'d shared memory, which generally requires the 
> use of
> plain old data (POD) types only, to avoid inadvertent constructor or
> destructor calls once the memory is freed.
> 
> QDateTime will (and is) leak applications to crash so I'd +1 the
> recommendation to change back to time_t (or at least some kind of 
> integral
> type), and the type is internal-only so there's no API concern. Just 
> don't
> forget to bump the defined KPIXMAPCACHE_VERSION so that old caches are 
> flushed
> ;).

Also, in practice, I believe time_t is everywhere we care about - we 
just have to take a little care about what API calls we use.

Alex