[KPhotoAlbum] Marble versioning

[Tobias Leupold]

Hi Harald!

> Cmake since 3.19 has the feature that you could write:
> 
> find_package(Marble 0.28.0...99.0.0 REQUIRED)
> 
> which would cover major version up to and including 99.

Thanks for this info! But I don't think we can depend on cmake 3.19, this is 
not even stable on Gentoo ... not even thinking about Debian stable ...

> With older Cmake, I am afraid you loose unless one can do something
> like this. First seek for any 0.x.y version bigger than 0.28.0 and
> if that fails search for any version 21.x.y:
> 
> find_package(Marble 0.28.0)
> if(NOT (${Maple_VERSION} MATCHES "0\..*") )
>     find_package(Marble 21.0.0 REQUIRED)
> endif()

This would probably be possible, BUT:

> After reading up on find_package I read that find_package does
> consider major version changes to be incompatible even if the version
> is bigger.

Which means that, if Marble continues/starts to identify it's version by the 
KDE SC version, we're lost. Because it starts with the year ... so, even if 
nothing has been changed, at the lastest after a year, we'll have a release 
that cmake will define as incompatible, beacuse the alleged major version has 
been bumped.

So they switched from not updating the version at all despite incompatible API 
changes to updating the major version without incompatible API changes.

The Marble guys should rethink their versioning :-(