[PATCH] msvcrt: Return error on invalid character in mbstowcs.

[Piotr Caban]

Signed-off-by: Piotr Caban 
---
  dlls/msvcrt/mbcs.c         | 15 +++++++++++----
  dlls/msvcrt/tests/string.c |  5 +++++
  2 files changed, 16 insertions(+), 4 deletions(-)