[PATCH] cmd: Set errorlevel to 0 when 'call' is invoked with an empty string.

[Marvin]

Hi,

While running your changed tests, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?

Full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=80315

Your paranoid android.


=== w864 (64 bit report) ===

cmd.exe:
batch.c:321: Test failed: unexpected char 0x31 position 0 in line 1361 (got '1', wanted '0')