# HG changeset patch
# User Kevin Bullock <kbullock@ringworld.org>
# Date 2012-04-04 17:46:54
# Node ID c14898df3b927ff5e0189866534190f85981823f
# Parent  f64b25f147d7091fcc34a0f9f0ac6f5c704c2f1f

ui: swallow EBADF on stderr

ui.write_err already swallows EPIPE and EIO if a write to stderr fails.
On Mac OS X at least, a write to a closed file descriptor results in
EBADF. Before this patch, hg would exit with status 1 if a write to
stderr failed during startup (e.g. while trying to print a warning about
not finding an extension):

  $ ./hg --config extensions.foo= version 2>&-; echo $?
  1

With this patch, it correctly swallows stderr and continues to run the
command:

  $ ./hg --config extensions.foo= version 2>&-
  Mercurial Distributed SCM (version 2.1)
  ...

diff --git a/mercurial/ui.py b/mercurial/ui.py
--- a/mercurial/ui.py
+++ b/mercurial/ui.py
@@ -480,7 +480,7 @@ class ui(object):
             if not getattr(self.ferr, 'closed', False):
                 self.ferr.flush()
         except IOError, inst:
-            if inst.errno not in (errno.EPIPE, errno.EIO):
+            if inst.errno not in (errno.EPIPE, errno.EIO, errno.EBADF):
                 raise
 
     def flush(self):