diff -r b9dcee25be8e -r 9dc64c8414ca mercurial/util.py
--- a/mercurial/util.py	Sat Mar 03 18:59:54 2007 -0800
+++ b/mercurial/util.py	Sun Mar 04 09:03:21 2007 -0300
@@ -790,6 +790,14 @@
                 if inst.errno != 0: raise
                 self.close()
                 raise IOError(errno.EPIPE, 'Broken pipe')
+                
+        def flush(self):
+            try:
+                return self.fp.flush()
+            except IOError, inst:
+                if inst.errno != errno.EINVAL: raise
+                self.close()
+                raise IOError(errno.EPIPE, 'Broken pipe')
 
     sys.stdout = winstdout(sys.stdout)