annotate mercurial/helptext/hgignore.5.txt @ 45095:8e04607023e5

procutil: ensure that procutil.std{out,err}.write() writes all bytes

Python 3 offers different kind of streams and it’s not guaranteed for all of
them that calling write() writes all bytes.

When Python is started in unbuffered mode, sys.std{out,err}.buffer are
instances of io.FileIO, whose write() can write less bytes for
platform-specific reasons (e.g. Linux has a 0x7ffff000 bytes maximum and could
write less if interrupted by a signal; when writing to Windows consoles, it’s
limited to 32767 bytes to avoid the "not enough space" error). This can lead to
silent loss of data, both when using sys.std{out,err}.buffer (which may in fact
not be a buffered stream) and when using the text streams sys.std{out,err}
(I’ve created a CPython bug report for that:
https://bugs.python.org/issue41221).

Python may fix the problem at some point. For now, we implement our own wrapper
for procutil.std{out,err} that calls the raw stream’s write() method until all
bytes have been written. We don’t use sys.std{out,err} for larger writes, so I
think it’s not worth the effort to patch them.

==========
 hgignore
==========

---------------------------------
syntax for Mercurial ignore files
---------------------------------

:Author:         Vadim Gelfer <[e-mail]>
:Organization:   Mercurial
:Manual section: 5
:Manual group:   Mercurial Manual

.. include:: hgignore.5.gendoc.txt

Author
======
Vadim Gelfer <[e-mail]>

Mercurial was written by Matt Mackall <[e-mail]>.

See Also
========
|hg(1)|_, |hgrc(5)|_

Copying
=======
This manual page is copyright 2006 Vadim Gelfer.
Mercurial is copyright 2005-2020 Matt Mackall.
Free use of this software is granted under the terms of the GNU General
Public License version 2 or any later version.

.. include:: common.txt