d3d: Make sure vertexbuffer lock doesn't return a NULL pointer.
[wine] / dlls / msvcrt40 /
drwxr-xr-x   ..
-rw-r--r-- 309 Makefile.in
-rw-r--r-- 1195 msvcrt40.c
-rw-r--r-- 47141 msvcrt40.spec