This is the SC331-6 Water prayer fix patch, sent to me by Dylan.

Apply within the src/ directory.

-- Jason Short

--- pray.c.old  Sat Sep  9 00:19:36 2000
+++ pray.c      Sat Sep  9 00:21:57 2000
@@ -867,7 +867,8 @@
 
     for(otmp = level.objects[u.ux][u.uy]; otmp; otmp = otmp->nexthere) {
        /* turn water into (un)holy water */
-       if (otmp->otyp == POT_WATER && (boolean)otmp->blessed != bless_water) {
+       if (otmp->otyp == POT_WATER && ((boolean)otmp->blessed != bless_water 
+            || (boolean)otmp->cursed == bless_water)) {
            otmp->blessed = bless_water;
            otmp->cursed = !bless_water;
            otmp->bknown = bc_known;