[PATCH 5/7] gdi32: Support NULL prev_value in NtGdiGetAndSetDCDword.

[Jacek Caban]

Signed-off-by: Jacek Caban <jacek(a)codeweavers.com>
---
  dlls/gdi32/dc.c | 17 ++++++++++-------
  1 file changed, 10 insertions(+), 7 deletions(-)