Bug 449107

Created attachment 145895 [details]
Change QScopedPointer get to data (fix FTBFS with Qt 5.9.5)

SUMMARY

digiKam 7.5.0 FTBFS with Qt 5.9.5 due introducing use of code requiring a newer Qt version.

STEPS TO REPRODUCE
1. Download digiKam 7.5.0 source and extract.
2. Attempt building source using pbuilder in a clean chroot with all appropriate build dependencies.
3. Build fails with errors as described below.

OBSERVED RESULT

The build fails with two distinct errors:

1) due use of QScopedPointer get function (Qt >= 5.11) in this file:

core/utilities/geolocation/geoiface/tiles/abstractmarkertiler.cpp

2) due use of key_value_iterator (Qt >= 5.10) in this file (iNaturalist):

core/dplugins/generic/webservices/inaturalist/inattalker.cpp

EXPECTED RESULT

That the build succeeds with Qt 5.9.5 as Qt 5.9 is (still, for now!) listed as a sufficient minimum Qt build dependency for digiKam.

SOFTWARE/OS VERSIONS
Windows: n/a
macOS: n/a
Linux/KDE Plasma: Ubuntu 18.04 / KDE 5.44
(available in About System)
KDE Plasma Version: 5.44
KDE Frameworks Version: 5.44
Qt Version: 5.9.5

ADDITIONAL INFORMATION

Changing the QScopedPointer get call to a data call fixes the first issue, as per bug 440313 (see attached patch). However, the use of key_value_iterator is more complex (for myself, not a C++ or Qt programmer!) and after a couple hours looking at how to rework the new slotTimeout function in the iNaturalist plugin with Qt 5.9 compatible iterators it was not obvious to me what would be functionally equivalent.

So for a successful "unofficial" Ubuntu 18.04 build at the digiKam PPA that I maintain the temporary solution was to remove the entire new slotTimeout function from the iNaturalist plugin, specifically removing relevant code from these two files:

core/dplugins/generic/webservices/inaturalist/inattalker.cpp
core/dplugins/generic/webservices/inaturalist/inattalker.h

No doubt there is a way to rework slotTimeout to use Qt 5.9 compatible iterators, such that anyone running an older system who uploads to iNaturalist will have the new timeout functionality as well.

Official documentation of relevance for the two issues:

1) https://doc.qt.io/archives/qt-5.11/qscopedpointer.html
2) https://doc.qt.io/archives/qt-5.10/qhash.html