[MERGE] ``BZR_LOG=disable`` suppresses writing messages to .bzr.log.

[Bernhard Voelker]

why not let the OS decide what to do with it?
I think

         _bzr_log_filename = '/dev/null'

is fully okay - every write to it will be automatically thrown
away by the kernel.

With your solution, we'd make '/dev/null' and 'NUL' magic words,
but from OS side they aren't! They're just character devices 
handled by a device driver, in this case the sink.

Bye,
Berny

Alexander Belchenko wrote:

=== modified file 'bzrlib/trace.py'
--- bzrlib/trace.py	2008-01-22 05:00:42 +0000
+++ bzrlib/trace.py	2008-01-28 22:48:19 +0000
@@ -177,6 +177,12 @@
             home = os.path.expanduser('~')
         _bzr_log_filename = os.path.join(home, '.bzr.log')
     else:
+        if sys.platform == 'win32':
+            if tracefilename.lower() == 'nul':
+                return
+        else:
+            if tracefilename == '/dev/null':
+                return
         _bzr_log_filename = tracefilename
 
     _bzr_log_filename = os.path.expanduser(_bzr_log_filename)