These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] x11-libs/libXtst-1.2.5::gentoo  USE="-doc" 285 KiB
[ebuild  N     ] x11-libs/libfakekey-0.3-r1::gentoo  USE="-debug -doc" 10 KiB
[ebuild  N     ] x11-misc/matchbox-keyboard-0.1-r2::gentoo  USE="cairo -debug" 101 KiB

Total: 3 packages (3 new), Size of downloads: 396 KiB