pushvars: move fb extension pushvars to core

pushvars: move fb extension pushvars to core

pushvars extension in fbext adds a --pushvars flag to push command using which
one send strings to server which becomes environment variables there prepended
with HG_USERVAR_. These variables can then be used to run hooks on the server.
The extension is moved directly to core and unbundling of the strings and
converting them to environment variables at server is disabled by default for
security reasons. One can turn that on by following config:

[push]
pushvars.server = true

This patch also adds the test for the extension.

Differential Revision: https://phab.mercurial-scm.org/D210

--- a/mercurial/bundle2.py	Fri Aug 04 12:21:23 2017 -0700
+++ b/mercurial/bundle2.py	Mon Jul 31 09:59:42 2017 +0530
@@ -1879,3 +1879,17 @@
 
     cache.write()
     op.ui.debug('applied %i hgtags fnodes cache entries\n' % count)
+
+@parthandler('pushvars')
+def bundle2getvars(op, part):
+    '''unbundle a bundle2 containing shellvars on the server'''
+    # An option to disable unbundling on server-side for security reasons
+    if op.ui.configbool('push', 'pushvars.server', False):
+        hookargs = {}
+        for key, value in part.advisoryparams:
+            key = key.upper()
+            # We want pushed variables to have USERVAR_ prepended so we know
+            # they came from the --pushvar flag.
+            key = "USERVAR_" + key
+            hookargs[key] = value
+        op.addhookargs(hookargs)

--- a/mercurial/commands.py	Fri Aug 04 12:21:23 2017 -0700
+++ b/mercurial/commands.py	Mon Jul 31 09:59:42 2017 +0530
@@ -3970,6 +3970,7 @@
     ('b', 'branch', [],
      _('a specific branch you would like to push'), _('BRANCH')),
     ('', 'new-branch', False, _('allow pushing a new branch')),
+    ('', 'pushvars', [], _('variables that can be sent to server (ADVANCED)')),
     ] + remoteopts,
     _('[-f] [-r REV]... [-e CMD] [--remotecmd CMD] [DEST]'))
 def push(ui, repo, dest=None, **opts):
@@ -4007,6 +4008,25 @@
     Please see :hg:`help urls` for important details about ``ssh://``
     URLs. If DESTINATION is omitted, a default path will be used.
 
+    .. container:: verbose
+
+        The --pushvars option sends strings to the server that become
+        environment variables prepended with ``HG_USERVAR_``. For example,
+        ``--pushvars ENABLE_FEATURE=true``, provides the server side hooks with
+        ``HG_USERVAR_ENABLE_FEATURE=true`` as part of their environment.
+
+        pushvars can provide for user-overridable hooks as well as set debug
+        levels. One example is having a hook that blocks commits containing
+        conflict markers, but enables the user to override the hook if the file
+        is using conflict markers for testing purposes or the file format has
+        strings that look like conflict markers.
+
+        By default, servers will ignore `--pushvars`. To enable it add the
+        following to your configuration file
+
+            [push]
+            pushvars.server = true
+
     Returns 0 if push was successful, 1 if nothing to push.
     """
 
@@ -4059,11 +4079,28 @@
                 return not result
     finally:
         del repo._subtoppath
+
+    pushvars = opts.get('pushvars')
+    if pushvars:
+        shellvars = {}
+        for raw in pushvars:
+            if '=' not in raw:
+                msg = ("unable to parse variable '%s', should follow "
+                        "'KEY=VALUE' or 'KEY=' format")
+                raise error.Abort(msg % raw)
+            k, v = raw.split('=', 1)
+            shellvars[k] = v
+
+        repo._shellvars = shellvars
+
     pushop = exchange.push(repo, other, opts.get('force'), revs=revs,
                            newbranch=opts.get('new_branch'),
                            bookmarks=opts.get('bookmark', ()),
                            opargs=opts.get('opargs'))
 
+    if pushvars:
+        del repo._shellvars
+
     result = not pushop.cgresult
 
     if pushop.bkresult is not None:

--- a/mercurial/exchange.py	Fri Aug 04 12:21:23 2017 -0700
+++ b/mercurial/exchange.py	Mon Jul 31 09:59:42 2017 +0530
@@ -893,6 +893,14 @@
                         pushop.bkresult = 1
     return handlereply
 
+@b2partsgenerator('pushvars', idx=0)
+def _getbundlesendvars(pushop, bundler):
+    '''send shellvars via bundle2'''
+    if getattr(pushop.repo, '_shellvars', ()):
+        part = bundler.newpart('pushvars')
+
+        for key, value in pushop.repo._shellvars.iteritems():
+            part.addparam(key, value, mandatory=False)
 
 def _pushbundle2(pushop):
     """push data to the remote using bundle2

--- a/tests/test-completion.t	Fri Aug 04 12:21:23 2017 -0700
+++ b/tests/test-completion.t	Mon Jul 31 09:59:42 2017 +0530
@@ -228,7 +228,7 @@
   log: follow, follow-first, date, copies, keyword, rev, removed, only-merges, user, only-branch, branch, prune, patch, git, limit, no-merges, stat, graph, style, template, include, exclude
   merge: force, rev, preview, tool
   pull: update, force, rev, bookmark, branch, ssh, remotecmd, insecure
-  push: force, rev, bookmark, branch, new-branch, ssh, remotecmd, insecure
+  push: force, rev, bookmark, branch, new-branch, pushvars, ssh, remotecmd, insecure
   remove: after, force, subrepos, include, exclude
   serve: accesslog, daemon, daemon-postexec, errorlog, port, address, prefix, name, web-conf, webdir-conf, pid-file, stdio, cmdserver, templates, style, ipv6, certificate, subrepos
   status: all, modified, added, removed, deleted, clean, unknown, ignored, no-status, terse, copies, print0, rev, change, include, exclude, subrepos, template

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-pushvars.t	Mon Jul 31 09:59:42 2017 +0530
@@ -0,0 +1,71 @@
+Setup
+
+  $ PYTHONPATH=$TESTDIR/..:$PYTHONPATH
+  $ export PYTHONPATH
+
+  $ cat > $TESTTMP/pretxnchangegroup.sh << EOF
+  > #!/bin/sh
+  > env | egrep "^HG_USERVAR_(DEBUG|BYPASS_REVIEW)" | sort
+  > exit 0
+  > EOF
+  $ chmod +x $TESTTMP/pretxnchangegroup.sh
+  $ cat >> $HGRCPATH << EOF
+  > [hooks]
+  > pretxnchangegroup = $TESTTMP/pretxnchangegroup.sh
+  > [experimental]
+  > bundle2-exp = true
+  > EOF
+
+  $ hg init repo
+  $ hg clone -q repo child
+  $ cd child
+
+Test pushing vars to repo with pushvars.server not set
+
+  $ echo b > a
+  $ hg commit -Aqm a
+  $ hg push --pushvars "DEBUG=1" --pushvars "BYPASS_REVIEW=true"
+  pushing to $TESTTMP/repo (glob)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+
+Setting pushvars.sever = true and then pushing.
+
+  $ echo [push] >> $HGRCPATH
+  $ echo "pushvars.server = true" >> $HGRCPATH
+  $ echo b >> a
+  $ hg commit -Aqm a
+  $ hg push --pushvars "DEBUG=1" --pushvars "BYPASS_REVIEW=true"
+  pushing to $TESTTMP/repo (glob)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  HG_USERVAR_BYPASS_REVIEW=true
+  HG_USERVAR_DEBUG=1
+
+Test pushing var with empty right-hand side
+
+  $ echo b >> a
+  $ hg commit -Aqm a
+  $ hg push --pushvars "DEBUG="
+  pushing to $TESTTMP/repo (glob)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  HG_USERVAR_DEBUG=
+
+Test pushing bad vars
+
+  $ echo b >> a
+  $ hg commit -Aqm b
+  $ hg push --pushvars "DEBUG"
+  pushing to $TESTTMP/repo (glob)
+  abort: unable to parse variable 'DEBUG', should follow 'KEY=VALUE' or 'KEY=' format
+  [255]