Do nothing in ShowWindow(SW_SHOW) if a window is already visible.
[wine] / dlls / psapi /
drwxr-xr-x   ..
-rw-r--r-- 40 .cvsignore
-rw-r--r-- 197 Makefile.in
-rw-r--r-- 1026 psapi.spec
-rw-r--r-- 13264 psapi_main.c