git only tracks the histories of full directories, not
that of individual files. Sometimes, SVN users will
place[1] a regular file in the directory designated
for subdirectories of branches or tags.
Thanks to jrockway on #git for pointing this out.
[1] mistakenly or otherwise, such as a README
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>