Mercurial > hg
view mercurial/txnutil.py @ 45068:8cd18aba5e6c
tests: proof test-stdio.py against buffer fill-up
With the previous code, it could in theory happen that the pipe / PTY buffer of
the child stdout / stderr fills up and the process never finishes.
To prevent that, we read all of the stream before waiting for the end of the
process. To ensure that the stream reaches EOF when the child finishes, we must
close the parent "copy" of the child stdout / stderr.
author | Manuel Jacob <me@manueljacob.de> |
---|---|
date | Tue, 07 Jul 2020 11:06:37 +0200 |
parents | 687b865b95ad |
children | 89a2afe31e82 |
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# txnutil.py - transaction related utilities # # Copyright FUJIWARA Katsunori <foozy@lares.dti.ne.jp> 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(b'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(b'%s.pending' % filename, **kwargs), True) except IOError as inst: if inst.errno != errno.ENOENT: raise return (vfs(filename, **kwargs), False)