tripping over objects under water

- cannot trip over submerged objects when you're water walking

doc/fixes34.1

@@ -42,6 +42,7 @@ animal_parts are not always appropriate for ravens
 prevent panic if tombstone window cannot be created
 clarify travel command behavior in the Guidebook
 touch_artifact checks needed when snagging w/bullwhip and stealing
+cannot trip over submerged objects if you're water walking
 
 
 Platform- and/or Interface-Specific Fixes

src/timeout.c

@@ -621,6 +621,8 @@ slip_or_trip()
 	if (u.usteed) on_foot = FALSE;
 #endif
 
+	if (otmp && on_foot && !u.uinwater && is_pool(u.ux, u.uy)) otmp = 0;
+
 	if (otmp && on_foot) {		/* trip over something in particular */
 	    /*
 		If there is only one item, it will have just been named