cmd: Don't read past end of thisVar in WCMD_expand_envvar (valgrind)

[Dan Kegel]

On Tue, May 24, 2011 at 10:26 PM, Marvin <testbot at testbot.winehq.org> wrote:
> === WNT4WSSP6 (32 bit) ===
> batch.c:223: Test failed: unexpected char 0x54 position 0 in line 86 (got 'This Line Is Never Reached.  If this runs, it is a bug.', wanted '65536')

Well, foo.  Guess NT is different. I'll rework the tests sometime and resubmit.

> === WXPPROSP3 (32 bit) ===
> batch.c:223: Test failed: unexpected char 0x30 position 0 in line 92 (got '0 should be 3 now', wanted '3 should be 3 now')

This one surprised me, doesn't seem to match local testing on XP.