Exception display in trac.cgi incorrect

[daniel]

The exception handler shows the wrong traceback when an unknown/unhandled exception is thrown.
Instead of showing the relevant traceback, it always shows 'database is locked'.

Example:

Oops...

Trac detected an internal error:

database is locked

Traceback (most recent call last):
  File "/home/daniel/Work/trac/trunk/cgi-bin/trac.cgi", line 25, in ?
    trac.core.cgi_start()
  File "/home/daniel/trac/trac/core.py", line 427, in cgi_start
    send_pretty_error(e, open_environment())
  File "/home/daniel/trac/trac/core.py", line 167, in open_environment
    version = env.get_version()
  File "/home/daniel/Work/trac/trunk/trac/Environment.py", line 136, in get_version
    cursor.execute("SELECT value FROM system WHERE name='database_version'")
  File "/usr/lib/python2.3/site-packages/sqlite/main.py", line 237, in execute
    self.con._begin()
  File "/usr/lib/python2.3/site-packages/sqlite/main.py", line 508, in _begin
    self.db.execute("BEGIN")
OperationalError: database is locked

[jonas]

Fixed in [480].