templatekw: compare target context and its parent exactly (issue4690) Before this patch, template keywords `{file_mods}`, `{file_adds}` and `{file_dels}` use values gotten by `repo.status(ctx.p1().node(), ctx.node())`. But this doesn't work as expected if `ctx` is `memctx` or `workingcommitctx`. Typical case of templating with these contexts is customization of the text shown in the commit message editor by `[committemplate]` configuration. In this case, `ctx.node()` returns None and it causes comparison between `ctx.p1()` and `workingctx`. `workingctx` lists up all changed files in the working directory even at selective committing. BTW, `{files}` uses `ctx.files()` and it works as expected. To compare target context and its parent exactly, this patch passes `ctx.p1()` and `ctx` without `node()`-nize. This avoids unexpected comparison with `workingctx`. This patch uses a little redundant template configurations in `test-commit.t`, but they are needed to avoid regression around problems fixed by a4958cdb2202 and 1e6fb8db666e: accessing on `ctx` may break `ctx._status` field.

Issue1678: IndexError when pushing

setting up base repo
  $ hg init a
  $ cd a
  $ touch a
  $ hg ci -Am a
  adding a
  $ cd ..

cloning base repo
  $ hg clone a b
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd b

setting up cset to push
  $ hg up null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ touch a
different msg so we get a clog new entry
  $ hg ci -Am b
  adding a
  created new head

pushing
  $ hg push -f ../a
  pushing to ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)

  $ cd ..