Mercurial > hg
view mercurial/help/environment.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 | aef2b98d9352 |
children |
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HG Path to the 'hg' executable, automatically passed when running hooks, extensions or external tools. If unset or empty, this is the hg executable's name if it's frozen, or an executable named 'hg' (with %PATHEXT% [defaulting to COM/EXE/BAT/CMD] extensions on Windows) is searched. HGEDITOR This is the name of the editor to run when committing. See EDITOR. (deprecated, see :hg:`help config.ui.editor`) HGENCODING This overrides the default locale setting detected by Mercurial. This setting is used to convert data including usernames, changeset descriptions, tag names, and branches. This setting can be overridden with the --encoding command-line option. HGENCODINGMODE This sets Mercurial's behavior for handling unknown characters while transcoding user input. The default is "strict", which causes Mercurial to abort if it can't map a character. Other settings include "replace", which replaces unknown characters, and "ignore", which drops them. This setting can be overridden with the --encodingmode command-line option. HGENCODINGAMBIGUOUS This sets Mercurial's behavior for handling characters with "ambiguous" widths like accented Latin characters with East Asian fonts. By default, Mercurial assumes ambiguous characters are narrow, set this variable to "wide" if such characters cause formatting problems. HGMERGE An executable to use for resolving merge conflicts. The program will be executed with three arguments: local file, remote file, ancestor file. (deprecated, see :hg:`help config.ui.merge`) HGRCPATH A list of files or directories to search for configuration files. Item separator is ":" on Unix, ";" on Windows. If HGRCPATH is not set, platform default search path is used. If empty, only the .hg/hgrc from the current repository is read. For each element in HGRCPATH: - if it's a directory, all files ending with .rc are added - otherwise, the file itself will be added HGPLAIN When set, this disables any configuration settings that might change Mercurial's default output. This includes encoding, defaults, verbose mode, debug mode, quiet mode, tracebacks, and localization. This can be useful when scripting against Mercurial in the face of existing user configuration. In addition to the features disabled by ``HGPLAIN=``, the following values can be specified to adjust behavior: ``+strictflags`` Restrict parsing of command line flags. Equivalent options set via command line flags or environment variables are not overridden. See :hg:`help scripting` for details. HGPLAINEXCEPT This is a comma-separated list of features to preserve when HGPLAIN is enabled. Currently the following values are supported: ``alias`` Don't remove aliases. ``color`` Don't disable colored output. ``i18n`` Preserve internationalization. ``revsetalias`` Don't remove revset aliases. ``templatealias`` Don't remove template aliases. ``progress`` Don't hide progress output. Setting HGPLAINEXCEPT to anything (even an empty string) will enable plain mode. HGUSER This is the string used as the author of a commit. If not set, available values will be considered in this order: - HGUSER (deprecated) - configuration files from the HGRCPATH - EMAIL - interactive prompt - LOGNAME (with ``@hostname`` appended) (deprecated, see :hg:`help config.ui.username`) EMAIL May be used as the author of a commit; see HGUSER. LOGNAME May be used as the author of a commit; see HGUSER. VISUAL This is the name of the editor to use when committing. See EDITOR. EDITOR Sometimes Mercurial needs to open a text file in an editor for a user to modify, for example when writing commit messages. The editor it uses is determined by looking at the environment variables HGEDITOR, VISUAL and EDITOR, in that order. The first non-empty one is chosen. If all of them are empty, the editor defaults to 'vi'. PYTHONPATH This is used by Python to find imported modules and may need to be set appropriately if this Mercurial is not installed system-wide.