https://build.opensuse.org/build/openSUSE:Factory:Staging:Gcc7/standard/x86_64/kdebase4-workspace/_log

[  193s]
/home/abuild/rpmbuild/BUILD/kde-workspace-4.11.22/libs/oxygen/oxygenhelper.cpp:
In member function 'bool Oxygen::Helper::hasHint(WId, Atom) const':
[  193s]
/home/abuild/rpmbuild/BUILD/kde-workspace-4.11.22/libs/oxygen/oxygenhelper.cpp:1092:21:
error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
[  193s]          if( data == None || n != 1 ) return false;
[  193s]                      ^~~~
[  193s] make[2]: *** [libs/oxygen/CMakeFiles/oxygenstyle.dir/build.make:127:
libs/oxygen/CMakeFiles/oxygenstyle.dir/oxygenhelper.cpp.o] Error 1

Can be tested in openSUSE:Factory:Staging:Gcc7 project.