Document empty environment variables not being passed to hooks under Windows.

doc/hgrc.5.txt

@@ -1,534 +1,539 b''
 HGRC(5)
 =======
 Bryan O'Sullivan <[e-mail]>
 
 NAME
 ----
 hgrc - configuration files for Mercurial
 
 SYNOPSIS
 --------
 
 The Mercurial system uses a set of configuration files to control
 aspects of its behaviour.
 
 FILES
 -----
 
 Mercurial reads configuration data from several files, if they exist.
 The names of these files depend on the system on which Mercurial is
 installed.
 
 (Unix)    <install-root>/etc/mercurial/hgrc.d/*.rc::
 (Unix)    <install-root>/etc/mercurial/hgrc::
     Per-installation configuration files, searched for in the
     directory where Mercurial is installed.  For example, if installed
     in /shared/tools, Mercurial will look in
     /shared/tools/etc/mercurial/hgrc.  Options in these files apply to
     all Mercurial commands executed by any user in any directory.
 
 (Unix)    /etc/mercurial/hgrc.d/*.rc::
 (Unix)    /etc/mercurial/hgrc::
 (Windows) C:\Mercurial\Mercurial.ini::
     Per-system configuration files, for the system on which Mercurial
     is running.  Options in these files apply to all Mercurial
     commands executed by any user in any directory.  Options in these
     files override per-installation options.
 
 (Unix)    $HOME/.hgrc::
 (Windows) C:\Documents and Settings\USERNAME\Mercurial.ini::
 (Windows) $HOME\Mercurial.ini::
     Per-user configuration file, for the user running Mercurial.
     Options in this file apply to all Mercurial commands executed by
     any user in any directory.  Options in this file override
     per-installation and per-system options.
     On Windows system, one of these is chosen exclusively according
     to definition of HOME environment variable.
 
 (Unix, Windows) <repo>/.hg/hgrc::
     Per-repository configuration options that only apply in a
     particular repository.  This file is not version-controlled, and
     will not get transferred during a "clone" operation.  Options in
     this file override options in all other configuration files.
     On Unix, most of this file will be ignored if it doesn't belong
     to a trusted user or to a trusted group.  See the documentation
     for the trusted section below for more details.
 
 SYNTAX
 ------
 
 A configuration file consists of sections, led by a "[section]" header
 and followed by "name: value" entries; "name=value" is also accepted.
 
     [spam]
     eggs=ham
     green=
        eggs
 
 Each line contains one entry.  If the lines that follow are indented,
 they are treated as continuations of that entry.
 
 Leading whitespace is removed from values.  Empty lines are skipped.
 
 The optional values can contain format strings which refer to other
 values in the same section, or values in a special DEFAULT section.
 
 Lines beginning with "#" or ";" are ignored and may be used to provide
 comments.
 
 SECTIONS
 --------
 
 This section describes the different sections that may appear in a
 Mercurial "hgrc" file, the purpose of each section, its possible
 keys, and their possible values.
 
 decode/encode::
   Filters for transforming files on checkout/checkin. This would
   typically be used for newline processing or other
   localization/canonicalization of files.
 
   Filters consist of a filter pattern followed by a filter command.
   Filter patterns are globs by default, rooted at the repository
   root.  For example, to match any file ending in ".txt" in the root
   directory only, use the pattern "*.txt".  To match any file ending
   in ".c" anywhere in the repository, use the pattern "**.c".
 
   The filter command can start with a specifier, either "pipe:" or
   "tempfile:".  If no specifier is given, "pipe:" is used by default.
 
   A "pipe:" command must accept data on stdin and return the
   transformed data on stdout.
 
   Pipe example:
 
     [encode]
     # uncompress gzip files on checkin to improve delta compression
     # note: not necessarily a good idea, just an example
     *.gz = pipe: gunzip
 
     [decode]
     # recompress gzip files when writing them to the working dir (we
     # can safely omit "pipe:", because it's the default)
     *.gz = gzip
 
   A "tempfile:" command is a template.  The string INFILE is replaced
   with the name of a temporary file that contains the data to be
   filtered by the command.  The string OUTFILE is replaced with the
   name of an empty temporary file, where the filtered data must be
   written by the command.
 
   NOTE: the tempfile mechanism is recommended for Windows systems,
   where the standard shell I/O redirection operators often have
   strange effects.  In particular, if you are doing line ending
   conversion on Windows using the popular dos2unix and unix2dos
   programs, you *must* use the tempfile mechanism, as using pipes will
   corrupt the contents of your files.
 
   Tempfile example:
 
     [encode]
     # convert files to unix line ending conventions on checkin
     **.txt = tempfile: dos2unix -n INFILE OUTFILE
 
     [decode]
     # convert files to windows line ending conventions when writing
     # them to the working dir
     **.txt = tempfile: unix2dos -n INFILE OUTFILE
 
 defaults::
   Use the [defaults] section to define command defaults, i.e. the 
   default options/arguments to pass to the specified commands.
   
   The following example makes 'hg log' run in verbose mode, and
   'hg status' show only the modified files, by default.
   
     [defaults]
     log = -v
     status = -m
   
   The actual commands, instead of their aliases, must be used when 
   defining command defaults. The command defaults will also be
   applied to the aliases of the commands defined.
 
 diff::
   Settings used when displaying diffs. They are all boolean and
   defaults to False.
   git;;
     Use git extended diff format.
   nodates;;
     Don't include dates in diff headers.
   showfunc;;
     Show which function each change is in.
   ignorews;;
     Ignore white space when comparing lines.
   ignorewsamount;;
     Ignore changes in the amount of white space.
   ignoreblanklines;;
     Ignore changes whose lines are all blank.
 
 email::
   Settings for extensions that send email messages.
   from;;
     Optional.  Email address to use in "From" header and SMTP envelope
     of outgoing messages.
   to;;
     Optional.  Comma-separated list of recipients' email addresses.
   cc;;
     Optional.  Comma-separated list of carbon copy recipients'
     email addresses.
   bcc;;
     Optional.  Comma-separated list of blind carbon copy
     recipients' email addresses.  Cannot be set interactively.
   method;;
     Optional.  Method to use to send email messages.  If value is
     "smtp" (default), use SMTP (see section "[smtp]" for
     configuration).  Otherwise, use as name of program to run that
     acts like sendmail (takes "-f" option for sender, list of
     recipients on command line, message on stdin).  Normally, setting
     this to "sendmail" or "/usr/sbin/sendmail" is enough to use
     sendmail to send messages.
 
   Email example:
 
     [email]
     from = Joseph User <[e-mail]>
     method = /usr/sbin/sendmail
 
 extensions::
   Mercurial has an extension mechanism for adding new features. To
   enable an extension, create an entry for it in this section.
 
   If you know that the extension is already in Python's search path,
   you can give the name of the module, followed by "=", with nothing
   after the "=".
 
   Otherwise, give a name that you choose, followed by "=", followed by
   the path to the ".py" file (including the file name extension) that
   defines the extension.
 
   Example for ~/.hgrc:
 
     [extensions]
     # (the mq extension will get loaded from mercurial's path)
     hgext.mq =
     # (this extension will get loaded from the file specified)
     myfeature = ~/.hgext/myfeature.py
 
 hooks::
   Commands or Python functions that get automatically executed by
   various actions such as starting or finishing a commit. Multiple
   hooks can be run for the same action by appending a suffix to the
   action. Overriding a site-wide hook can be done by changing its
   value or setting it to an empty string.
 
   Example .hg/hgrc:
 
     [hooks]
     # do not use the site-wide hook
     incoming =
     incoming.email = /my/email/hook
     incoming.autobuild = /my/build/hook
 
   Most hooks are run with environment variables set that give added
   useful information.  For each hook below, the environment variables
   it is passed are listed with names of the form "$HG_foo".
 
   changegroup;;
     Run after a changegroup has been added via push, pull or
     unbundle. ID of the first new changeset is in $HG_NODE.  URL from
     which changes came is in $HG_URL.
   commit;;
     Run after a changeset has been created in the local repository.
     ID of the newly created changeset is in $HG_NODE.  Parent
     changeset IDs are in $HG_PARENT1 and $HG_PARENT2.
   incoming;;
     Run after a changeset has been pulled, pushed, or unbundled into
     the local repository.  The ID of the newly arrived changeset is in
     $HG_NODE.  URL that was source of changes came is in $HG_URL.
   outgoing;;
     Run after sending changes from local repository to another.  ID of
     first changeset sent is in $HG_NODE.  Source of operation is in
     $HG_SOURCE; see "preoutgoing" hook for description.
   prechangegroup;;
     Run before a changegroup is added via push, pull or unbundle.
     Exit status 0 allows the changegroup to proceed.  Non-zero status
     will cause the push, pull or unbundle to fail.  URL from which
     changes will come is in $HG_URL.
   precommit;;
     Run before starting a local commit.  Exit status 0 allows the
     commit to proceed.  Non-zero status will cause the commit to fail.
     Parent changeset IDs are in $HG_PARENT1 and $HG_PARENT2.
   preoutgoing;;
     Run before computing changes to send from the local repository to
     another.  Non-zero status will cause failure.  This lets you
     prevent pull over http or ssh.  Also prevents against local pull,
     push (outbound) or bundle commands, but not effective, since you
     can just copy files instead then.  Source of operation is in
     $HG_SOURCE.  If "serve", operation is happening on behalf of
     remote ssh or http repository.  If "push", "pull" or "bundle",
     operation is happening on behalf of repository on same system.
   pretag;;
     Run before creating a tag.  Exit status 0 allows the tag to be
     created.  Non-zero status will cause the tag to fail.  ID of
     changeset to tag is in $HG_NODE.  Name of tag is in $HG_TAG.  Tag
     is local if $HG_LOCAL=1, in repo if $HG_LOCAL=0.
   pretxnchangegroup;;
     Run after a changegroup has been added via push, pull or unbundle,
     but before the transaction has been committed.  Changegroup is
     visible to hook program.  This lets you validate incoming changes
     before accepting them.  Passed the ID of the first new changeset
     in $HG_NODE.  Exit status 0 allows the transaction to commit.
     Non-zero status will cause the transaction to be rolled back and
     the push, pull or unbundle will fail.  URL that was source of
     changes is in $HG_URL.
   pretxncommit;;
     Run after a changeset has been created but the transaction not yet
     committed.  Changeset is visible to hook program.  This lets you
     validate commit message and changes.  Exit status 0 allows the
     commit to proceed.  Non-zero status will cause the transaction to
     be rolled back.  ID of changeset is in $HG_NODE.  Parent changeset
     IDs are in $HG_PARENT1 and $HG_PARENT2.
   preupdate;;
     Run before updating the working directory.  Exit status 0 allows
     the update to proceed.  Non-zero status will prevent the update.
     Changeset ID of first new parent is in $HG_PARENT1.  If merge, ID
     of second new parent is in $HG_PARENT2.
   tag;;
     Run after a tag is created.  ID of tagged changeset is in
     $HG_NODE.  Name of tag is in $HG_TAG.  Tag is local if
     $HG_LOCAL=1, in repo if $HG_LOCAL=0.
   update;;
     Run after updating the working directory.  Changeset ID of first
     new parent is in $HG_PARENT1.  If merge, ID of second new parent
     is in $HG_PARENT2.  If update succeeded, $HG_ERROR=0.  If update
     failed (e.g. because conflicts not resolved), $HG_ERROR=1.
 
   Note: In earlier releases, the names of hook environment variables
   did not have a "HG_" prefix.  The old unprefixed names are no longer
   provided in the environment.
 
+  Note2: Environment variables with empty values may not be passed to
+  hooks on platforms like Windows. For instance, $HG_PARENT2 will
+  not be available under Windows for non-merge changesets while being
+  set to an empty value under Unix-like systems.
+
   The syntax for Python hooks is as follows:
 
     hookname = python:modulename.submodule.callable
 
   Python hooks are run within the Mercurial process.  Each hook is
   called with at least three keyword arguments: a ui object (keyword
   "ui"), a repository object (keyword "repo"), and a "hooktype"
   keyword that tells what kind of hook is used.  Arguments listed as
   environment variables above are passed as keyword arguments, with no
   "HG_" prefix, and names in lower case.
 
   If a Python hook returns a "true" value or raises an exception, this
   is treated as failure of the hook.
 
 http_proxy::
   Used to access web-based Mercurial repositories through a HTTP
   proxy.
   host;;
     Host name and (optional) port of the proxy server, for example
     "myproxy:8000".
   no;;
     Optional.  Comma-separated list of host names that should bypass
     the proxy.
   passwd;;
     Optional.  Password to authenticate with at the proxy server.
   user;;
     Optional.  User name to authenticate with at the proxy server.
 
 smtp::
   Configuration for extensions that need to send email messages.
   host;;
     Host name of mail server, e.g. "mail.example.com".
   port;;
     Optional.  Port to connect to on mail server.  Default: 25.
   tls;;
     Optional.  Whether to connect to mail server using TLS.  True or
     False.  Default: False.
   username;;
     Optional.  User name to authenticate to SMTP server with.
     If username is specified, password must also be specified.
     Default: none.
   password;;
     Optional.  Password to authenticate to SMTP server with.
     If username is specified, password must also be specified.
     Default: none.
   local_hostname;;
     Optional.  It's the hostname that the sender can use to identify itself
     to the MTA.
 
 paths::
   Assigns symbolic names to repositories.  The left side is the
   symbolic name, and the right gives the directory or URL that is the
   location of the repository.  Default paths can be declared by
   setting the following entries.
   default;;
     Directory or URL to use when pulling if no source is specified.
     Default is set to repository from which the current repository
     was cloned.
   default-push;;
     Optional.  Directory or URL to use when pushing if no destination
     is specified.
 
 server::
   Controls generic server settings.
   uncompressed;;
     Whether to allow clients to clone a repo using the uncompressed
     streaming protocol.  This transfers about 40% more data than a
     regular clone, but uses less memory and CPU on both server and
     client.  Over a LAN (100Mbps or better) or a very fast WAN, an
     uncompressed streaming clone is a lot faster (~10x) than a regular
     clone.  Over most WAN connections (anything slower than about
     6Mbps), uncompressed streaming is slower, because of the extra
     data transfer overhead.  Default is False.
 
 trusted::
   For security reasons, Mercurial will not use the settings in
   the .hg/hgrc file from a repository if it doesn't belong to a
   trusted user or to a trusted group.  The main exception is the
   web interface, which automatically uses some safe settings, since
   it's common to serve repositories from different users.
 
   This section specifies what users and groups are trusted.  The
   current user is always trusted.  To trust everybody, list a user
   or a group with name "*".
 
   users;;
     Comma-separated list of trusted users.
   groups;;
     Comma-separated list of trusted groups.
 
 ui::
   User interface controls.
   debug;;
     Print debugging information.  True or False.  Default is False.
   editor;;
     The editor to use during a commit.  Default is $EDITOR or "vi".
   fallbackencoding;;
     Encoding to try if it's not possible to decode the changelog using
     UTF-8.  Default is ISO-8859-1.
   ignore;;
     A file to read per-user ignore patterns from. This file should be in
     the same format as a repository-wide .hgignore file. This option
     supports hook syntax, so if you want to specify multiple ignore
     files, you can do so by setting something like
     "ignore.other = ~/.hgignore2". For details of the ignore file
     format, see the hgignore(5) man page.
   interactive;;
     Allow to prompt the user.  True or False.  Default is True.
   logtemplate;;
     Template string for commands that print changesets.
   style;;
     Name of style to use for command output.
   merge;;
     The conflict resolution program to use during a manual merge.
     Default is "hgmerge".
   quiet;;
     Reduce the amount of output printed.  True or False.  Default is False.
   remotecmd;;
     remote command to use for clone/push/pull operations. Default is 'hg'.
   ssh;;
     command to use for SSH connections. Default is 'ssh'.
   strict;;
     Require exact command names, instead of allowing unambiguous
     abbreviations.  True or False.  Default is False.
   timeout;;
     The timeout used when a lock is held (in seconds), a negative value
     means no timeout. Default is 600.
   username;;
     The committer of a changeset created when running "commit".
     Typically a person's name and email address, e.g. "Fred Widget
     <[e-mail]>".  Default is $EMAIL or username@hostname.
     If the username in hgrc is empty, it has to be specified manually or
     in a different hgrc file (e.g. $HOME/.hgrc, if the admin set "username ="
     in the system hgrc).
   verbose;;
     Increase the amount of output printed.  True or False.  Default is False.
 
 
 web::
   Web interface configuration.
   accesslog;;
     Where to output the access log. Default is stdout.
   address;;
     Interface address to bind to. Default is all.
   allow_archive;;
     List of archive format (bz2, gz, zip) allowed for downloading.
     Default is empty.
   allowbz2;;
     (DEPRECATED) Whether to allow .tar.bz2 downloading of repo revisions.
     Default is false.
   allowgz;;
     (DEPRECATED) Whether to allow .tar.gz downloading of repo revisions.
     Default is false.
   allowpull;;
     Whether to allow pulling from the repository. Default is true.
   allow_push;;
     Whether to allow pushing to the repository.  If empty or not set,
     push is not allowed.  If the special value "*", any remote user
     can push, including unauthenticated users.  Otherwise, the remote
     user must have been authenticated, and the authenticated user name
     must be present in this list (separated by whitespace or ",").
     The contents of the allow_push list are examined after the
     deny_push list.
   allowzip;;
     (DEPRECATED) Whether to allow .zip downloading of repo revisions.
     Default is false. This feature creates temporary files.
   baseurl;;
     Base URL to use when publishing URLs in other locations, so
     third-party tools like email notification hooks can construct URLs.
     Example: "http://hgserver/repos/"
   contact;;
     Name or email address of the person in charge of the repository.
     Default is "unknown".
   deny_push;;
     Whether to deny pushing to the repository.  If empty or not set,
     push is not denied.  If the special value "*", all remote users
     are denied push.  Otherwise, unauthenticated users are all denied,
     and any authenticated user name present in this list (separated by
     whitespace or ",") is also denied.  The contents of the deny_push
     list are examined before the allow_push list.
   description;;
     Textual description of the repository's purpose or contents.
     Default is "unknown".
   errorlog;;
     Where to output the error log. Default is stderr.
   ipv6;;
     Whether to use IPv6. Default is false.
   name;;
     Repository name to use in the web interface. Default is current
     working directory.
   maxchanges;;
     Maximum number of changes to list on the changelog. Default is 10.
   maxfiles;;
     Maximum number of files to list per changeset. Default is 10.
   port;;
     Port to listen on. Default is 8000.
   push_ssl;;
     Whether to require that inbound pushes be transported over SSL to
     prevent password sniffing.  Default is true.
   stripes;;
     How many lines a "zebra stripe" should span in multiline output.
     Default is 1; set to 0 to disable.
   style;;
     Which template map style to use.
   templates;;
     Where to find the HTML templates. Default is install path.
 
 
 AUTHOR
 ------
 Bryan O'Sullivan <[e-mail]>.
 
 Mercurial was written by Matt Mackall <[e-mail]>.
 
 SEE ALSO
 --------
 hg(1), hgignore(5)
 
 COPYING
 -------
 This manual page is copyright 2005 Bryan O'Sullivan.
 Mercurial is copyright 2005, 2006 Matt Mackall.
 Free use of this software is granted under the terms of the GNU General
 Public License (GPL).