copy: rewrite walkpat() to depend less on dirstate...
copy: rewrite walkpat() to depend less on dirstate
I want to add a `hg cp/mv -r <rev>` option to mark files as
copied/moved in an existing commit (amending that commit). The code
needs to not depend on the dirstate for that.
Differential Revision:
https://phab.mercurial-scm.org/D8031
