Simple scenario to test it:

*Pre-conditions:*
INHERIT += "buildhistory"
BUILDHISTORY_RESET = "1"
BUILDHISTORY_PRESERVE:append = " files-in-package.txt"

*Run:*
bitbake -c cleansstate base-passwd && bitbake base-passwd
*Check:*
cat PATH_TO_BUILD_dir/buildhistory/packages/core2-64-poky-linux/base-passwd/base-passwd-dbg/files-in-package.txt
(File exists and content ok)
*Run:*
rm -rf tmp && bitbake base-passwd (it will use sstate cache)
*Check:*
cat PATH_TO_BUILD_dir/buildhistory/packages/core2-64-poky-linux/base-passwd/base-passwd-dbg/files-in-package.txt
(File wont exist)

Cheers,
Pedro