view tests/test-issue1993.t @ 39110:f0c2653ca706

merge: add tests for commit with no content change

It isn't easy to say when to reuse the p1 manifest. Basically, that's only
when wctx.files() is empty, but we need to know that wctx.files() is not
the same as repo['.'].files() after the commit.

This patch adds several examples of commits with empty ctx/wctx.files().
I don't think this is exhaustive, but it contains at least one failure
mode in which a converted repo result in a different hash.

I also note that the manifest revlog does NOT follow the DAG shape of the
changelog since p1 manifest is reused if wctx.files() is empty even at merge.
I don't know whether it is intentional or not, but it's the behavior since
2011, 301725c3df9a "localrepo: reuse parent manifest in commitctx if no files
have changed."

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Am0
  adding a
  $ echo b > b
  $ hg ci -Am1
  adding b
  $ hg tag -r0 default
  warning: tag default conflicts with existing branch name
  $ hg log
  changeset:   2:30a83d1e4a1e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag default for changeset f7b1eb17ad24
  
  changeset:   1:925d80f479bb
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  changeset:   0:f7b1eb17ad24
  tag:         default
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  $ hg update 'tag(default)'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg parents
  changeset:   0:f7b1eb17ad24
  tag:         default
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  $ hg update 'branch(default)'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg parents
  changeset:   2:30a83d1e4a1e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag default for changeset f7b1eb17ad24
  

  $ cd ..