tests: add test showing --continue not preserving --date and --user flags...
tests: add test showing --continue not preserving --date and --user flags
This patch adds test showing that we don't preserve the user passed --date and
--user values in `hg graft`. I was fixing that and realized this is untested.
Adding tests before so that behavior change or the fix is easy to realize.
Differential Revision:
https://phab.mercurial-scm.org/D3658