Define relative paths when KDE_INSTALL_USE_QT_SYS_PATHS is enabled

When building multiple KDE projects, installing them to "$DESTDIR"
and having cmake look for kde dependencies in "$DESTDIR" using
"CMAKE_PREFIX_PATH=$DESTDIR/usr", we currently get failures when
calling find_package() on projects that use KDE_INSTALL_QTPLUGINDIR,
KDE_INSTALL_QTQMLDIR and KDE_INSTALL_QTQUICKIMPORTSDIR because these
are defined as absolute paths when KDE_INSTALL_USE_QT_SYS_PATHS is
enabled.

This commit defines these paths relative to qmake's QT_INSTALL_PREFIX
property instead when KDE is install to the same prefix as Qt. This
fixes DESTDIR installations because with relative paths, CMake will
search for these paths in "$DESTDIR" as well as "/".

We limit this change to the scenario where the Qt and CMake install
prefixes are the same because always doing this would break backwards
compatibility as qml and plugins would be installed into CMAKE_INSTALL_PREFIX
instead of QT_INSTALL_PREFIX after this change.

0 files changed, 0 insertions, 0 deletions