wrong error from curses.wrapper if curses initialization fails

One way to reproduce is trying under IDLE.app in OS X:

  import curses
  def scr(a):
    a.getch()

  curses.wrapper(scr)

Traceback before patch:
  UnboundLocalError: local variable 'stdscr' referenced before 
assignment

Traceback after patch:
  _curses.error: setupterm: could not find terminal

APPLIES         2.6, 2.7, 3.0, 3.1

This is a one line patch on wrapper.py.  Sorry I can't do any more with this cos I only have a windows box.

[FYI: Comments at the beginning of a patch file are ignored by the standard Unix-y patch utilities.  They are there for a reason.]

I can confirm that both the problem exists and the patch works on Python 2.6 and 3.1. I love to see it committed.

A simpler way to reproduce:
TERM= python -c 'import curses; curses.wrapper(lambda a:a.getch())'

I looked at adding an automated test case for this but it is a little tricky to make it bulletproof across all environments. Since the problem is really a one-time coding error, perhaps a permanent test case can be omitted?

New changeset c731e02472c5 by Ned Deily in branch '2.7':
Issue #5622: Fix curses.wrapper to raise correct exception if curses
http://hg.python.org/cpython/rev/c731e02472c5

New changeset 6b6b8af33811 by Ned Deily in branch '3.1':
Issue #5622: Fix curses.wrapper to raise correct exception if curses
http://hg.python.org/cpython/rev/6b6b8af33811

New changeset e6c45cd46cb2 by Ned Deily in branch '3.2':
Issue #5622: merge fix from 3.1.
http://hg.python.org/cpython/rev/e6c45cd46cb2

New changeset ec717db610df by Ned Deily in branch 'default':
Issue #5622: merge fix from 3.2.
http://hg.python.org/cpython/rev/ec717db610df