hook: flush stdout before redirecting to stderr
When hook output redirection is enabled (e.g. when cloning over ssh), hook
output on stdout is redirected to stderr, to prevent the repository data on
stdout from being corrupted.
In certain cases, the redirection could cause part of the repository data to
end up on stderr as well. In case of a clone, this causes:
"abort: consistency error in delta!"
This was seen with a clone over ssh, an outgoing hook present (any
non-python type, e.g. 'pwd'), on certain repositories only,
probably depending on the distribution of the sent data)
This patch updates the hook redirection code to flush stdout before
redirecting, removing the problem.
# hook.py - hook support for mercurial
#
# Copyright 2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from i18n import _
import os, sys
import extensions, util
def _pythonhook(ui, repo, name, hname, funcname, args, throw):
'''call python hook. hook is callable object, looked up as
name in python module. if callable returns "true", hook
fails, else passes. if hook raises exception, treated as
hook failure. exception propagates if throw is "true".
reason for "true" meaning "hook failed" is so that
unmodified commands (e.g. mercurial.commands.update) can
be run as hooks without wrappers to convert return values.'''
ui.note(_("calling hook %s: %s\n") % (hname, funcname))
obj = funcname
if not util.safehasattr(obj, '__call__'):
d = funcname.rfind('.')
if d == -1:
raise util.Abort(_('%s hook is invalid ("%s" not in '
'a module)') % (hname, funcname))
modname = funcname[:d]
oldpaths = sys.path
if util.mainfrozen():
# binary installs require sys.path manipulation
modpath, modfile = os.path.split(modname)
if modpath and modfile:
sys.path = sys.path[:] + [modpath]
modname = modfile
try:
obj = __import__(modname)
except ImportError:
e1 = sys.exc_type, sys.exc_value, sys.exc_traceback
try:
# extensions are loaded with hgext_ prefix
obj = __import__("hgext_%s" % modname)
except ImportError:
e2 = sys.exc_type, sys.exc_value, sys.exc_traceback
if ui.tracebackflag:
ui.warn(_('exception from first failed import attempt:\n'))
ui.traceback(e1)
if ui.tracebackflag:
ui.warn(_('exception from second failed import attempt:\n'))
ui.traceback(e2)
raise util.Abort(_('%s hook is invalid '
'(import of "%s" failed)') %
(hname, modname))
sys.path = oldpaths
try:
for p in funcname.split('.')[1:]:
obj = getattr(obj, p)
except AttributeError:
raise util.Abort(_('%s hook is invalid '
'("%s" is not defined)') %
(hname, funcname))
if not util.safehasattr(obj, '__call__'):
raise util.Abort(_('%s hook is invalid '
'("%s" is not callable)') %
(hname, funcname))
try:
try:
# redirect IO descriptors the the ui descriptors so hooks
# that write directly to these don't mess up the command
# protocol when running through the command server
old = sys.stdout, sys.stderr, sys.stdin
sys.stdout, sys.stderr, sys.stdin = ui.fout, ui.ferr, ui.fin
r = obj(ui=ui, repo=repo, hooktype=name, **args)
except KeyboardInterrupt:
raise
except Exception, exc:
if isinstance(exc, util.Abort):
ui.warn(_('error: %s hook failed: %s\n') %
(hname, exc.args[0]))
else:
ui.warn(_('error: %s hook raised an exception: '
'%s\n') % (hname, exc))
if throw:
raise
ui.traceback()
return True
finally:
sys.stdout, sys.stderr, sys.stdin = old
if r:
if throw:
raise util.Abort(_('%s hook failed') % hname)
ui.warn(_('warning: %s hook failed\n') % hname)
return r
def _exthook(ui, repo, name, cmd, args, throw):
ui.note(_("running hook %s: %s\n") % (name, cmd))
env = {}
for k, v in args.iteritems():
if util.safehasattr(v, '__call__'):
v = v()
if isinstance(v, dict):
# make the dictionary element order stable across Python
# implementations
v = ('{' +
', '.join('%r: %r' % i for i in sorted(v.iteritems())) +
'}')
env['HG_' + k.upper()] = v
if repo:
cwd = repo.root
else:
cwd = os.getcwd()
if 'HG_URL' in env and env['HG_URL'].startswith('remote:http'):
r = util.system(cmd, environ=env, cwd=cwd, out=ui)
else:
r = util.system(cmd, environ=env, cwd=cwd, out=ui.fout)
if r:
desc, r = util.explainexit(r)
if throw:
raise util.Abort(_('%s hook %s') % (name, desc))
ui.warn(_('warning: %s hook %s\n') % (name, desc))
return r
_redirect = False
def redirect(state):
global _redirect
_redirect = state
def hook(ui, repo, name, throw=False, **args):
r = False
oldstdout = -1
if _redirect:
try:
stdoutno = sys.__stdout__.fileno()
stderrno = sys.__stderr__.fileno()
# temporarily redirect stdout to stderr, if possible
if stdoutno >= 0 and stderrno >= 0:
sys.__stdout__.flush()
oldstdout = os.dup(stdoutno)
os.dup2(stderrno, stdoutno)
except AttributeError:
# __stdout/err__ doesn't have fileno(), it's not a real file
pass
try:
for hname, cmd in ui.configitems('hooks'):
if hname.split('.')[0] != name or not cmd:
continue
if util.safehasattr(cmd, '__call__'):
r = _pythonhook(ui, repo, name, hname, cmd, args, throw) or r
elif cmd.startswith('python:'):
if cmd.count(':') >= 2:
path, cmd = cmd[7:].rsplit(':', 1)
path = util.expandpath(path)
if repo:
path = os.path.join(repo.root, path)
mod = extensions.loadpath(path, 'hghook.%s' % hname)
hookfn = getattr(mod, cmd)
else:
hookfn = cmd[7:].strip()
r = _pythonhook(ui, repo, name, hname, hookfn, args, throw) or r
else:
r = _exthook(ui, repo, hname, cmd, args, throw) or r
finally:
if _redirect and oldstdout >= 0:
os.dup2(oldstdout, stdoutno)
os.close(oldstdout)
return r