Mercurial > hg
view mercurial/help/hgignore.txt @ 40626:87a872555e90
revlog: detect incomplete revlog reads
_readsegment() is supposed to return N bytes of revlog revision
data starting at a file offset. Surprisingly, its behavior before
this patch never verified that it actually read and returned N
bytes! Instead, it would perform the read(), then return whatever
data was available. And even more surprisingly, nothing in the
call chain appears to have been validating that it received all
the data it was expecting.
This behavior could lead to partial or incomplete revision chunks
being operated on. This could result in e.g. cached deltas being
applied against incomplete base revisions. The delta application
process would happily perform this operation. Only hash
verification would detect the corruption and save us.
This commit changes the behavior of raw revlog reading to validate
that we actually read() the number of bytes that were requested.
We will raise a more specific error faster, rather than possibly
have it go undetected or manifest later in the call stack, at
delta application or hash verification.
Differential Revision: https://phab.mercurial-scm.org/D5266
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Tue, 13 Nov 2018 12:30:59 -0800 |
parents | 7072b91ccd20 |
children | 4fab8a7d2d72 |
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Synopsis ======== The Mercurial system uses a file called ``.hgignore`` in the root directory of a repository to control its behavior when it searches for files that it is not currently tracking. Description =========== The working directory of a Mercurial repository will often contain files that should not be tracked by Mercurial. These include backup files created by editors and build products created by compilers. These files can be ignored by listing them in a ``.hgignore`` file in the root of the working directory. The ``.hgignore`` file must be created manually. It is typically put under version control, so that the settings will propagate to other repositories with push and pull. An untracked file is ignored if its path relative to the repository root directory, or any prefix path of that path, is matched against any pattern in ``.hgignore``. For example, say we have an untracked file, ``file.c``, at ``a/b/file.c`` inside our repository. Mercurial will ignore ``file.c`` if any pattern in ``.hgignore`` matches ``a/b/file.c``, ``a/b`` or ``a``. In addition, a Mercurial configuration file can reference a set of per-user or global ignore files. See the ``ignore`` configuration key on the ``[ui]`` section of :hg:`help config` for details of how to configure these files. To control Mercurial's handling of files that it manages, many commands support the ``-I`` and ``-X`` options; see :hg:`help <command>` and :hg:`help patterns` for details. Files that are already tracked are not affected by .hgignore, even if they appear in .hgignore. An untracked file X can be explicitly added with :hg:`add X`, even if X would be excluded by a pattern in .hgignore. Syntax ====== An ignore file is a plain text file consisting of a list of patterns, with one pattern per line. Empty lines are skipped. The ``#`` character is treated as a comment character, and the ``\`` character is treated as an escape character. Mercurial supports several pattern syntaxes. The default syntax used is Python/Perl-style regular expressions. To change the syntax used, use a line of the following form:: syntax: NAME where ``NAME`` is one of the following: ``regexp`` Regular expression, Python/Perl syntax. ``glob`` Shell-style glob. The chosen syntax stays in effect when parsing all patterns that follow, until another syntax is selected. Neither glob nor regexp patterns are rooted. A glob-syntax pattern of the form ``*.c`` will match a file ending in ``.c`` in any directory, and a regexp pattern of the form ``\.c$`` will do the same. To root a regexp pattern, start it with ``^``. Subdirectories can have their own .hgignore settings by adding ``subinclude:path/to/subdir/.hgignore`` to the root ``.hgignore``. See :hg:`help patterns` for details on ``subinclude:`` and ``include:``. .. note:: Patterns specified in other than ``.hgignore`` are always rooted. Please see :hg:`help patterns` for details. Example ======= Here is an example ignore file. :: # use glob syntax. syntax: glob *.elc *.pyc *~ # switch to regexp syntax. syntax: regexp ^\.pc/