view relnotes/5.1 @ 50336:cf4d2f31660d stable

chg: populate CHGHG if not set

Normally, chg determines which `hg` executable to use by first consulting the
`$CHGHG` and `$HG` environment variables, and if neither are present defaults
to the `hg` found in the user's `$PATH`. If built with the `HGPATHREL` compiler
flag, chg will instead assume that there exists an `hg` executable in the same
directory as the `chg` binary and attempt to use that.

This can cause problems in situations where there are multiple actively-used
Mercurial installations on the same system. When a `chg` client connects to a
running command server, the server process performs some basic validation to
determine whether a new command server needs to be spawned. These checks include
things like checking certain "sensitive" environment variables and config
sections, as well as checking whether the mtime of the extensions, hg's
`__version__.py` module, and the Python interpreter have changed.

Crucially, the command server doesn't explicitly check whether the executable it
is running from matches the executable that the `chg` client would have
otherwise invoked had there been no existing command server process. Without
`HGPATHREL`, this still gets implicitly checked during the validation step,
because the only way to specify an alternate hg executable (apart from `$PATH`)
is via the `$CHGHG` and `$HG` environment variables, both of which are checked.

With `HGPATHREL`, however, the command server has no way of knowing which hg
executable the client would have run. This means that a client located at
`/version_B/bin/chg` will happily connect to a command server running
`/version_A/bin/hg` instead of `/version_B/bin/hg` as expected. A simple
solution is to have the client set `$CHGHG` itself, which then allows the
command server's environment validation to work as intended.

I have tested this manually using two locally built hg installations and it
seems to work with no ill effects. That said, I'm not sure how to write an
automated test for this since the `chg` available to the tests isn't even built
with the `HGPATHREL` compiler flag to begin with.

== 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 `--force-close-branch` flag for `hg commit` to forcibly close
   branch from a non-head changeset.

 * The curses-based interface for commands like `hg commit -i` now supports
   a range-select mechanism. Select the first line using space like before,
   navigate to the last line, and press X (capital x) to set all items in
   the range at once. Lowercase x has been added as a synonym for space to
   help reinforce the mechanism, and pressing enter/return continues to be a
   synonym for "toggle the current line and move down to the next item in
   this section."

== 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).

 * shelve is no longer an extension now. it will be turned on by default.

 * 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.

 * merge abort has been disallowed in case an operation of higher
   precedence is in progress to avoid cases of partial abort of
   operations.

 * We used to automatically attempt to make extensions compatible with
   Python 3 (by translating their source code while loading it). We no
   longer do that.