hgweb: teach WSGI parser about query strings
Currently, req.form uses cgi.parse() to populate form data. Depending
on the request, form data can come from POST multipart/form-data,
application/x-www-form-urlencoded, or the URL query string.
Putting all these things into one data structure makes it difficult
to reason about how exactly parameters got to the request. It can
lead to wonkiness such as pulling parameters from both the URL and
POST data.
This commit teaches our WSGI request parser about argument data
in query strings. We populate fields containing the query string
data and only the query string data so it can't be confused with
POST data.
Differential Revision: https://phab.mercurial-scm.org/D2737
# Copyright (C) 2015 - Mike Edgar <adgar@google.com>
#
# This extension enables removal of file content at a given revision,
# rewriting the data/metadata of successive revisions to preserve revision log
# integrity.
"""erase file content at a given revision
The censor command instructs Mercurial to erase all content of a file at a given
revision *without updating the changeset hash.* This allows existing history to
remain valid while preventing future clones/pulls from receiving the erased
data.
Typical uses for censor are due to security or legal requirements, including::
* Passwords, private keys, cryptographic material
* Licensed data/code/libraries for which the license has expired
* Personally Identifiable Information or other private data
Censored nodes can interrupt mercurial's typical operation whenever the excised
data needs to be materialized. Some commands, like ``hg cat``/``hg revert``,
simply fail when asked to produce censored data. Others, like ``hg verify`` and
``hg update``, must be capable of tolerating censored data to continue to
function in a meaningful way. Such commands only tolerate censored file
revisions if they are allowed by the "censor.policy=ignore" config option.
"""
from __future__ import absolute_import
from mercurial.i18n import _
from mercurial.node import short
from mercurial import (
error,
filelog,
lock as lockmod,
registrar,
revlog,
scmutil,
util,
)
cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'
@command('censor',
[('r', 'rev', '', _('censor file from specified revision'), _('REV')),
('t', 'tombstone', '', _('replacement tombstone data'), _('TEXT'))],
_('-r REV [-t TEXT] [FILE]'))
def censor(ui, repo, path, rev='', tombstone='', **opts):
wlock = lock = None
try:
wlock = repo.wlock()
lock = repo.lock()
return _docensor(ui, repo, path, rev, tombstone, **opts)
finally:
lockmod.release(lock, wlock)
def _docensor(ui, repo, path, rev='', tombstone='', **opts):
if not path:
raise error.Abort(_('must specify file path to censor'))
if not rev:
raise error.Abort(_('must specify revision to censor'))
wctx = repo[None]
m = scmutil.match(wctx, (path,))
if m.anypats() or len(m.files()) != 1:
raise error.Abort(_('can only specify an explicit filename'))
path = m.files()[0]
flog = repo.file(path)
if not len(flog):
raise error.Abort(_('cannot censor file with no history'))
rev = scmutil.revsingle(repo, rev, rev).rev()
try:
ctx = repo[rev]
except KeyError:
raise error.Abort(_('invalid revision identifier %s') % rev)
try:
fctx = ctx.filectx(path)
except error.LookupError:
raise error.Abort(_('file does not exist at revision %s') % rev)
fnode = fctx.filenode()
headctxs = [repo[c] for c in repo.heads()]
heads = [c for c in headctxs if path in c and c.filenode(path) == fnode]
if heads:
headlist = ', '.join([short(c.node()) for c in heads])
raise error.Abort(_('cannot censor file in heads (%s)') % headlist,
hint=_('clean/delete and commit first'))
wp = wctx.parents()
if ctx.node() in [p.node() for p in wp]:
raise error.Abort(_('cannot censor working directory'),
hint=_('clean/delete/update first'))
flogv = flog.version & 0xFFFF
if flogv != revlog.REVLOGV1:
raise error.Abort(
_('censor does not support revlog version %d') % (flogv,))
tombstone = filelog.packmeta({"censored": tombstone}, "")
crev = fctx.filerev()
if len(tombstone) > flog.rawsize(crev):
raise error.Abort(_(
'censor tombstone must be no longer than censored data'))
# Using two files instead of one makes it easy to rewrite entry-by-entry
idxread = repo.svfs(flog.indexfile, 'r')
idxwrite = repo.svfs(flog.indexfile, 'wb', atomictemp=True)
if flog.version & revlog.FLAG_INLINE_DATA:
dataread, datawrite = idxread, idxwrite
else:
dataread = repo.svfs(flog.datafile, 'r')
datawrite = repo.svfs(flog.datafile, 'wb', atomictemp=True)
# Copy all revlog data up to the entry to be censored.
rio = revlog.revlogio()
offset = flog.start(crev)
for chunk in util.filechunkiter(idxread, limit=crev * rio.size):
idxwrite.write(chunk)
for chunk in util.filechunkiter(dataread, limit=offset):
datawrite.write(chunk)
def rewriteindex(r, newoffs, newdata=None):
"""Rewrite the index entry with a new data offset and optional new data.
The newdata argument, if given, is a tuple of three positive integers:
(new compressed, new uncompressed, added flag bits).
"""
offlags, comp, uncomp, base, link, p1, p2, nodeid = flog.index[r]
flags = revlog.gettype(offlags)
if newdata:
comp, uncomp, nflags = newdata
flags |= nflags
offlags = revlog.offset_type(newoffs, flags)
e = (offlags, comp, uncomp, r, link, p1, p2, nodeid)
idxwrite.write(rio.packentry(e, None, flog.version, r))
idxread.seek(rio.size, 1)
def rewrite(r, offs, data, nflags=revlog.REVIDX_DEFAULT_FLAGS):
"""Write the given full text to the filelog with the given data offset.
Returns:
The integer number of data bytes written, for tracking data offsets.
"""
flag, compdata = flog.compress(data)
newcomp = len(flag) + len(compdata)
rewriteindex(r, offs, (newcomp, len(data), nflags))
datawrite.write(flag)
datawrite.write(compdata)
dataread.seek(flog.length(r), 1)
return newcomp
# Rewrite censored revlog entry with (padded) tombstone data.
pad = ' ' * (flog.rawsize(crev) - len(tombstone))
offset += rewrite(crev, offset, tombstone + pad, revlog.REVIDX_ISCENSORED)
# Rewrite all following filelog revisions fixing up offsets and deltas.
for srev in xrange(crev + 1, len(flog)):
if crev in flog.parentrevs(srev):
# Immediate children of censored node must be re-added as fulltext.
try:
revdata = flog.revision(srev)
except error.CensoredNodeError as e:
revdata = e.tombstone
dlen = rewrite(srev, offset, revdata)
else:
# Copy any other revision data verbatim after fixing up the offset.
rewriteindex(srev, offset)
dlen = flog.length(srev)
for chunk in util.filechunkiter(dataread, limit=dlen):
datawrite.write(chunk)
offset += dlen
idxread.close()
idxwrite.close()
if dataread is not idxread:
dataread.close()
datawrite.close()