trac-admin: output stream in trouble

[Emmanuel Blot]

When trac-admin project permission list is invoked, the command fails with the following error:

Trac [/Users/eblot/Trac/Db/trunk]> permission list
Command failed: encode() argument 1 must be string, not None

The same error also occurs if the permissions are listed for a specific user.

The trouble comes from the print_table() method. When it attempts to retrieve the defaut encoding for the output stream, the defaut encoding may be defined to 'None' rather than being undefined. In such a case, the getattr() built-in function return 'None' instead of the fallback parameter ('utf-8').
This leads to evaluate None as the charset rather than 'utf-8'. Maybe this is Mac OS X -only issue, I did not test it on other platforms.

The following patch solves the issue - as I'm not sure it does the exact same thing that was originally expected, I did not commit it to the trunk. Let me know if you want me to commit it.

trac/util/text.py

@@ -110 +110 @@
 def print_table(data, headers=None, sep='  ', out=None):
     if out is None:
         out = sys.stdout
-    charset = getattr(out, 'encoding', 'utf-8')
+    charset = getattr(out, 'encoding', None) or 'utf-8'
     data = list(data)
     if headers:
         data.insert(0, headers)

[Emmanuel Blot]

I just bumped into this issue once more, this time with Linux Debian.

The same issue occurs when the trac-admin standard output is piped to the stdin of any other process.

If nobody objects, I'll apply this patch today.

[Christian Boos]

Reproduced on Windows as well, where your fix works as well. Please apply.

[Emmanuel Blot]

Applied in [5210]