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.
from mercurial import minirst
from mercurial.utils import stringutil
def debugformat(text, form, **kwargs):
blocks, pruned = minirst.parse(text, **kwargs)
if form == b'html':
print("html format:")
out = minirst.format(text, style=form, **kwargs)
else:
print("%d column format:" % form)
out = minirst.format(text, width=form, **kwargs)
print("-" * 70)
print(out[:-1].decode('utf8'))
if kwargs.get('keep'):
print("-" * 70)
print(stringutil.pprint(pruned).decode('utf8'))
print("-" * 70)
print()
def debugformats(title, text, **kwargs):
print("== %s ==" % title)
debugformat(text, 60, **kwargs)
debugformat(text, 30, **kwargs)
debugformat(text, b'html', **kwargs)
paragraphs = b"""
This is some text in the first paragraph.
A small indented paragraph.
It is followed by some lines
containing random whitespace.
\n \n \nThe third and final paragraph.
"""
debugformats('paragraphs', paragraphs)
definitions = b"""
A Term
Definition. The indented
lines make up the definition.
Another Term
Another definition. The final line in the
definition determines the indentation, so
this will be indented with four spaces.
A Nested/Indented Term
Definition.
"""
debugformats('definitions', definitions)
literals = br"""
The fully minimized form is the most
convenient form::
Hello
literal
world
In the partially minimized form a paragraph
simply ends with space-double-colon. ::
////////////////////////////////////////
long un-wrapped line in a literal block
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
::
This literal block is started with '::',
the so-called expanded form. The paragraph
with '::' disappears in the final output.
"""
debugformats('literals', literals)
lists = b"""
- This is the first list item.
Second paragraph in the first list item.
- List items need not be separated
by a blank line.
- And will be rendered without
one in any case.
We can have indented lists:
- This is an indented list item
- Another indented list item::
- A literal block in the middle
of an indented list.
(The above is not a list item since we are in the literal block.)
::
Literal block with no indentation (apart from
the two spaces added to all literal blocks).
1. This is an enumerated list (first item).
2. Continuing with the second item.
(1) foo
(2) bar
1) Another
2) List
Line blocks are also a form of list:
| This is the first line.
The line continues here.
| This is the second line.
Bullet lists are also detected:
* This is the first bullet
* This is the second bullet
It has 2 lines
* This is the third bullet
"""
debugformats('lists', lists)
options = b"""
There is support for simple option lists,
but only with long options:
-X, --exclude filter an option with a short and long option with an argument
-I, --include an option with both a short option and a long option
--all Output all.
--both Output both (this description is
quite long).
--long Output all day long.
--par This option has two paragraphs in its description.
This is the first.
This is the second. Blank lines may be omitted between
options (as above) or left in (as here).
The next paragraph looks like an option list, but lacks the two-space
marker after the option. It is treated as a normal paragraph:
--foo bar baz
"""
debugformats('options', options)
fields = b"""
:a: First item.
:ab: Second item. Indentation and wrapping
is handled automatically.
:c\:d: a key with colon
:efg\:\:hh: a key with many colon
Next list:
:small: The larger key below triggers full indentation here.
:much too large: This key is big enough to get its own line.
"""
debugformats('fields', fields)
containers = b"""
Normal output.
.. container:: debug
Initial debug output.
.. container:: verbose
Verbose output.
.. container:: debug
Debug output.
"""
debugformats('containers (normal)', containers)
debugformats('containers (verbose)', containers, keep=[b'verbose'])
debugformats('containers (debug)', containers, keep=[b'debug'])
debugformats(
'containers (verbose debug)', containers, keep=[b'verbose', b'debug']
)
roles = b"""Please see :hg:`add`."""
debugformats('roles', roles)
sections = b"""
Title
=====
Section
-------
Subsection
''''''''''
Markup: ``foo`` and :hg:`help`
------------------------------
"""
debugformats('sections', sections)
admonitions = b"""
.. note::
This is a note
- Bullet 1
- Bullet 2
.. warning:: This is a warning Second
input line of warning
.. danger::
This is danger
"""
debugformats('admonitions', admonitions)
comments = b"""
Some text.
.. A comment
.. An indented comment
Some indented text.
..
Empty comment above
"""
debugformats('comments', comments)
data = [
[b'a', b'b', b'c'],
[b'1', b'2', b'3'],
[b'foo', b'bar', b'baz this list is very very very long man'],
]
rst = minirst.maketable(data, 2, True)
table = b''.join(rst)
print(table.decode('utf8'))
debugformats('table', table)
data = [
[b's', b'long', b'line\ngoes on here'],
[b'', b'xy', b'tried to fix here\n by indenting'],
]
rst = minirst.maketable(data, 1, False)
table = b''.join(rst)
print(table.decode('utf8'))
debugformats('table+nl', table)