mercurial/txnutil.py

templatefilter: add support for 'long' to json()

When disabling the '#requires serve' check in test-hgwebdir.t and running it on
Windows, several 500 errors popped up when querying '?style=json', with the
following in the error log:

    File "...\\mercurial\\templater.py", line 393, in runfilter
      "keyword '%s'") % (filt.func_name, dt))
    Abort: template filter 'json' is not compatible with keyword 'lastchange'

The swallowed exception at that point was:

    File "...\\mercurial\\templatefilters.py", line 242, in json
      raise TypeError('cannot encode type %s' % obj.__class__.__name__)
    TypeError: cannot encode type long

This corresponds to 'lastchange' being populated by hgweb.common.get_stat(),
which uses os.stat().st_mtime.  os.stat_float_times() is being disabled in util,
so the type for the times is 'long' on Windows, and 'int' on Linux.

# txnutil.py - transaction related utilities
#
#  Copyright FUJIWARA Katsunori <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import errno

from . import (
    encoding,
)

def mayhavepending(root):
    '''return whether 'root' may have pending changes, which are
    visible to this process.
    '''
    return root == encoding.environ.get('HG_PENDING')

def trypending(root, vfs, filename, **kwargs):
    '''Open  file to be read according to HG_PENDING environment variable

    This opens '.pending' of specified 'filename' only when HG_PENDING
    is equal to 'root'.

    This returns '(fp, is_pending_opened)' tuple.
    '''
    if mayhavepending(root):
        try:
            return (vfs('%s.pending' % filename, **kwargs), True)
        except IOError as inst:
            if inst.errno != errno.ENOENT:
                raise
    return (vfs(filename, **kwargs), False)