procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
== 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.