Ignore EPIPE in pipefilter
This hides the following traceback (there's a race condition involved,
so you may have to try a few times to hit it):
$ hg sign --key key-that-does-not-exist
Signing 2062:4bad92f4ea65
gpg: skipped "key-that-does-not-exist": secret key not available
gpg: signing failed: secret key not available
Exception in thread Thread-1:
Traceback (most recent call last):
File "threading.py", line 442, in __bootstrap
self.run()
File "threading.py", line 422, in run
self.__target(*self.__args, **self.__kwargs)
File "mercurial/util.py", line 24, in writer
pin.close()
IOError: [Errno 32] Broken pipe
abort: Error while signing
header = header-raw.tmpl
footer = ''
changeset = changeset-raw.tmpl
difflineplus = '#line#'
difflineminus = '#line#'
difflineat = '#line#'
diffline = '#line#'
changesetparent = '# parent: #node#'
changesetchild = '# child: #node#'
filenodelink = ''
filerevision = 'Content-Type: #mimetype#\nContent-Disposition: filename=#file#\n\n#raw#'
fileline = '#line#'
diffblock = '#lines#'
filediff = filediff-raw.tmpl
fileannotate = fileannotate-raw.tmpl
annotateline = '#author#@#rev#: #line#'