relnotes: added description about statemod._statecheck

Differential Revision: https://phab.mercurial-scm.org/D6557

relnotes/next

@@ -1,59 +1,70
 == New Features ==
 
  * New config `commands.commit.post-status` shows status after successful
  commit.
 
  * `hg root` now has templating support, including support for showing
    where a repo share's source is. See `hg help -v root` for details.
 
 
 == New Experimental Features ==
 
  * New config `experimental.log.topo` makes `hg log -G` use
    topological sorting. This is especially useful for aliases since it
    lets the alias accept an `-r` option while still using topological
    sorting with or without the `-r` (unlike if you use the `sort(...,
    topo)` revset).
 
 
 == Bug Fixes  ==
 
  * issue4292: "hg log and {files} {file_adds} {file_mods} {file_dels}
    in template show wrong files on merged revision". See details in
    "Backwards Compatibility Changes".
 
 
 == Backwards Compatibility Changes ==
 
  * Removed (experimental) support for log graph lines mixing
    parent/grandparent styles. Setting
    e.g. `experimental.graphstyle.parent = !` and
    `experimental.graphstyle.grandparent = 3.` would use `!` for the
    first three lines of the graph and then `.`. This is no longer
    supported.
 
  * If `ui.origbackuppath` had been (incorrectly) configured to point
    to a file, we will now replace that file by a directory and put
    backups in that directory. This is similar to how we would
    previously replace files *in* the configured directory by
    subdirectories.
 
 * Template keyword `{file_mods}`, `{file_adds}`, and `{file_dels}`
    have changed behavior on merge commits. They used to be relative to
    the first parent, but they now consider both parents. `{file_adds}`
    shows files that exists in the commit but did not exist in either
    parent. `{file_dels}` shows files that do not exist in the commit
    but existed in either parent. `{file_mods}` show the remaining
    files from `{files}` that were not in the other two
    sets.
 
 
 == Internal API Changes ==
 
  * Matchers are no longer iterable. Use `match.files()` instead.
 
  * `match.visitdir()` and `match.visitchildrenset()` now expect the
    empty string instead of '.' to indicate the root directory.
 
  * `util.dirs()` and `util.finddirs()` now include an entry for the
    root directory (empty string).
+
+ * New API to manage unfinished operations: Earlier there were distinct APIs
+   which dealt with unfinished states and separate lists maintaining them
+   that are `cmdutil.afterresolvestates`, `cmdutil.unfinishedstates` and
+   `cmdutil.STATES`. Now these have been unified to a single
+   API which handles the various states and their utilities. This API
+   has been added to `state.py`. Now instead of adding to these 3 lists
+   independently a state for a new operation can be registered using
+   `addunfinished()` in `state` module.
+
+ * `cmdutil.checkunfinished()` now includes detection for merge too.