Don't crash if pDDSD is NULL on DirectDrawSurface::Lock.

dlls/ddraw/ddraw_utils.c

@@ -640,14 +640,17 @@ void DDRAW_dump_surface_desc(const DDSURFACEDESC2 *lpddsd)
         };
 #undef STRUCT
 
-    if (lpddsd->dwSize >= sizeof(DDSURFACEDESC2)) {
-        DDRAW_dump_members(lpddsd->dwFlags, lpddsd, members_caps2, 1);
+    if (NULL == lpddsd) {
+        DPRINTF("(null)\n");
     } else {
-        DDRAW_dump_members(lpddsd->dwFlags, lpddsd, members_caps, 1);
+      if (lpddsd->dwSize >= sizeof(DDSURFACEDESC2)) {
+          DDRAW_dump_members(lpddsd->dwFlags, lpddsd, members_caps2, 1);
+      } else {
+          DDRAW_dump_members(lpddsd->dwFlags, lpddsd, members_caps, 1);
+      }
+      DDRAW_dump_members(lpddsd->dwFlags, lpddsd, members,
+			 sizeof(members)/sizeof(members[0]));
     }
-                                                  
-    DDRAW_dump_members(lpddsd->dwFlags, lpddsd, members,
-                       sizeof(members)/sizeof(members[0]));
 }
 
 void DDRAW_dump_cooperativelevel(DWORD cooplevel)

dlls/ddraw/surface_main.c

@@ -1093,6 +1093,12 @@ Main_DirectDrawSurface_Lock(LPDIRECTDRAWSURFACE7 iface, LPRECT prect,
 	    WARN(" - unsupported locking flag : "); DDRAW_dump_lockflag(flags & ~(DDLOCK_WAIT|DDLOCK_READONLY|DDLOCK_WRITEONLY));
 	}
     }
+    if (NULL != h) {
+        return DDERR_INVALIDPARAMS;
+    }
+    if (NULL == pDDSD) {
+        return DDERR_INVALIDPARAMS; /** really ? */
+    }
 
     /* If the surface is already locked, return busy */
     if (This->locked) {