Bump min Qt version

[Maik Qualmann]

It's all correct with the Qt version check. My only thought was whether we 
could find another option for Qt::endl, as there would be a lot of Qt version 
checks. 

Maik

Am Dienstag, 15. Juni 2021, 23:09:28 CEST schrieb Anjani Kumar:
> What should I do? Keep doing this or not?
> 
> Thanks
> Anjani
> 
> On Jun 16 2021, at 2:23 am, Anjani Kumar <anjanik012 at gmail.com> wrote:
> > Something like this
> > 
> > 
> > #if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
> > 
> > QStringList tagsList = hierarchy.split(QLatin1Char('/'),
> > Qt::SkipEmptyParts);
> > 
> > #else
> > 
> > QStringList tagsList = hierarchy.split(QLatin1Char('/'),
> > QString::SkipEmptyParts);
> > 
> > #endif
> > I haven't pushed it yet though.
> > 
> > On Jun 16 2021, at 2:19 am, Anjani Kumar <anjanik012 at gmail.com> wrote:
> > > I already started this pre-processor branching. Not for Qt::endl but I
> > > have done it for QString::split() which is also present from Qt 5.14.> > 
> > > On Jun 16 2021, at 2:16 am, Maik Qualmann <metzpinguin at gmail.com> wrote:
> > > > But we already have a problem with Qt::endl, this only exists with
> > > > Qt-5.14. We should find another way of doing this than with
> > > > pre-processeur branching. Maybe define a macro.
> > > > 
> > > > Maik
> > > > 
> > > > Am Dienstag, 15. Juni 2021, 13:55:53 CEST schrieb Gilles Caulier:
> > > > > Hi,
> > > > > 
> > > > > No. We need to be compatible at least with Qt 5.12 LTS.
> > > > > Please make pre-processeur branching in source code by checking Qt
> > > > > version,
> > > > > as it already do in other place in digiKam.
> > > > > 
> > > > > exemple :
> > > > > https://invent.kde.org/graphics/digikam/-/blob/master/core/app/date/
> > > > > ddatepic ker.cpp#L547
> > > > > 
> > > > > Best
> > > > > 
> > > > > Gilles Caulier
> > > > > 
> > > > > Le mar. 15 juin 2021 à 13:52, Anjani Kumar <anjanik012 at gmail.com> a 
écrit :
> > > > > > The recent changes to
> > > > > > https://invent.kde.org/graphics/digikam/-/tree/gsoc21-qt6-port
> > > > > > makes it
> > > > > > compile only on newer Qt versions. So I it should be best Bump Qt
> > > > > > version
> > > > > > to 5.15.2. Should I make the change?
> > > > > > 
> > > > > > Thanks,
> > > > > > Anjani