Fix: wished-for items with unspecified erosion shouldn't be eroded

Another bug induced by allowing items to generate eroded. The wish
parser assumed that calling mksobj with init=TRUE would never produce
erosion, so it didn't previously need to clear eroded flags on the item.
Intended behavior is the same: the only erosion that should happen on a
wished item is if the wisher explicitly asked for it.

Author: copperwater

src/objnam.c

@@ -4706,6 +4706,9 @@ readobjnam(char* bp, struct obj* no_wish)
 
     /* set eroded and erodeproof */
     if (erosion_matters(d.otmp)) {
+        /* no wished-for item should be eroded if the wisher didn't specify it
+         * to be */
+        d.otmp->oeroded = d.otmp->oeroded2 = 0;
         if (d.eroded && (is_flammable(d.otmp) || is_rustprone(d.otmp)))
             d.otmp->oeroded = d.eroded;
         if (d.eroded2 && (is_corrodeable(d.otmp) || is_rottable(d.otmp)))