# HG changeset patch
# User Idan Kamara <idankk86@gmail.com>
# Date 2011-06-15 20:50:33
# Node ID 1bdbca0b66041e97a9c49d4e3a5ca1bc67082137
# Parent  5e9d691229d5d08046e8008aad864f714e982a3a

cmdutil: return a dummy, closable file object if it cannot be duped

If the ui I/O descriptors aren't real descriptors, they cannot be duped.

Instead, we return a wrapper object that behaves the same, and
can be closed (by overriding close and doing nothing).

diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -161,7 +161,22 @@ def makefileobj(repo, pat, node=None, to
 
     if not pat or pat == '-':
         fp = writable and repo.ui.fout or repo.ui.fin
-        return os.fdopen(os.dup(fp.fileno()), mode)
+        if hasattr(fp, 'fileno'):
+            return os.fdopen(os.dup(fp.fileno()), mode)
+        else:
+            # if this fp can't be duped properly, return
+            # a dummy object that can be closed
+            class wrappedfileobj(object):
+                noop = lambda x: None
+                def __init__(self, f):
+                    self.f = f
+                def __getattr__(self, attr):
+                    if attr == 'close':
+                        return self.noop
+                    else:
+                        return getattr(self.f, attr)
+
+            return wrappedfileobj(fp)
     if hasattr(pat, 'write') and writable:
         return pat
     if hasattr(pat, 'read') and 'r' in mode: