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.
Test the 'check-commit' script
==============================
A fine patch:
$ cat > patch-with-long-header.diff << EOF
> # HG changeset patch
> # User timeless <timeless@mozdev.org>
> # Date 1448911706 0
> # Mon Nov 30 19:28:26 2015 +0000
> # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
> # Parent 42aa0e570eaa364a622bc4443b0bcb79b1100a58
> # ClownJoke This is a veryly long header that should not be warned about because its not the description
> bundle2: use Oxford comma (issue123) (BC)
>
> diff --git a/hgext/transplant.py b/hgext/transplant.py
> --- a/hgext/transplant.py
> +++ b/hgext/transplant.py
> @@ -599,7 +599,7 @@
> return
> if not (opts.get('source') or revs or
> opts.get('merge') or opts.get('branch')):
> - raise error.Abort(_('no source URL, branch revision or revision '
> + raise error.Abort(_('no source URL, branch revision, or revision '
> 'list provided'))
> if opts.get('all'):
>
> + def blahblah(x):
> + pass
> EOF
$ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit
This would normally be against the rules, but it's okay because that's
what tagging and signing looks like:
$ cat > creates-a-tag.diff << EOF
> # HG changeset patch
> # User Augie Fackler <raf@durin42.com>
> # Date 1484787778 18000
> # Wed Jan 18 20:02:58 2017 -0500
> # Branch stable
> # Node ID c177635e4acf52923bc3aa9f72a5b1ad1197b173
> # Parent a1dd2c0c479e0550040542e392e87bc91262517e
> Added tag 4.1-rc for changeset a1dd2c0c479e
>
> diff --git a/.hgtags b/.hgtags
> --- a/.hgtags
> +++ b/.hgtags
> @@ -150,3 +150,4 @@ 438173c415874f6ac653efc1099dec9c9150e90f
> eab27446995210c334c3d06f1a659e3b9b5da769 4.0
> b3b1ae98f6a0e14c1e1ba806a6c18e193b6dae5c 4.0.1
> e69874dc1f4e142746ff3df91e678a09c6fc208c 4.0.2
> +a1dd2c0c479e0550040542e392e87bc91262517e 4.1-rc
> EOF
$ $TESTDIR/../contrib/check-commit < creates-a-tag.diff
A patch with lots of errors:
$ cat > patch-with-long-header.diff << EOF
> # HG changeset patch
> # User timeless
> # Date 1448911706 0
> # Mon Nov 30 19:28:26 2015 +0000
> # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
> # Parent 42aa0e570eaa364a622bc4443b0bcb79b1100a58
> # ClownJoke This is a veryly long header that should not be warned about because its not the description
> transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
>
> diff --git a/hgext/transplant.py b/hgext/transplant.py
> --- a/hgext/transplant.py
> +++ b/hgext/transplant.py
> @@ -599,7 +599,7 @@
> return
> if not (opts.get('source') or revs or
> opts.get('merge') or opts.get('branch')):
> - raise error.Abort(_('no source URL, branch revision or revision '
> + raise error.Abort(_('no source URL, branch revision, or revision '
> 'list provided'))
> if opts.get('all'):
> EOF
$ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit
1: username is not an email address
# User timeless
7: summary keyword should be most user-relevant one-word command or topic
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
7: (BC) needs to be uppercase
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
7: use (issueDDDD) instead of bug
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
7: no space allowed between issue and number
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
7: summary line too long (limit is 78)
transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
[1]
A patch with other errors:
$ cat > patch-with-long-header.diff << EOF
> # HG changeset patch
> # User timeless
> # Date 1448911706 0
> # Mon Nov 30 19:28:26 2015 +0000
> # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
> # Parent 42aa0e570eaa364a622bc4443b0bcb79b1100a58
> # ClownJoke This is a veryly long header that should not be warned about because its not the description
> This has no topic and ends with a period.
>
> diff --git a/hgext/transplant.py b/hgext/transplant.py
> --- a/hgext/transplant.py
> +++ b/hgext/transplant.py
> @@ -599,7 +599,7 @@
> if opts.get('all'):
>
>
> +
> + some = otherjunk
> +
> +
> + def blah_blah(x):
> + pass
> +
>
> EOF
$ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit
1: username is not an email address
# User timeless
7: don't capitalize summary lines
This has no topic and ends with a period.
7: summary line doesn't start with 'topic: '
This has no topic and ends with a period.
7: don't add trailing period on summary line
This has no topic and ends with a period.
[1]