- zero the velocity of crunched sprites.

Since their size is zeroed, they are no longer subject to collision detection and may slide out of the level otherwise.

src/playsim/p_mobj.cpp

@@ -1186,6 +1186,7 @@ bool AActor::Grind(bool items)
 			flags3 |= MF3_DONTGIB;
 			Height = 0;
 			radius = 0;
+			Vel.Zero();
 			return false;
 		}
 
@@ -1212,6 +1213,7 @@ bool AActor::Grind(bool items)
 			flags3 |= MF3_DONTGIB;
 			Height = 0;
 			radius = 0;
+			Vel.Zero();
 			SetState (state);
 			if (isgeneric)	// Not a custom crush state, so colorize it appropriately.
 			{
@@ -1248,6 +1250,7 @@ bool AActor::Grind(bool items)
 				flags3 |= MF3_DONTGIB;
 				Height = 0;
 				radius = 0;
+				Vel.Zero();
 				return false;
 			}