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
<table class="changelogEntry parity#parity#">
<tr>
<th class="age" width="15%">#date|age# ago:</th>
<th class="firstline">#desc|strip|firstline|escape#</th>
</tr>
<tr>
<th class="changesetRev">changeset #rev#:</th>
<td class="changesetNode"><a href="?cs=#node|short#">#node|short#</a></td>
</tr>
#parent%changelogparent#
#child%changelogchild#
#changelogtag#
<tr>
<th class="author">author:</th>
<td class="author">#author|obfuscate#</td>
</tr>
<tr>
<th class="date">date:</th>
<td class="date">#date|date#</td>
</tr>
<tr>
<th class="files"><a href="?mf=#manifest|short#;path=/">files</a>:</th>
<td class="files">#files#</td>
</tr>
</table>