fix issue #949 - dropping welded iron ball

If punished and the attached iron ball was both cursed and wielded,
falling while going down stairs would drop it instead of leaving it
welded to hero's hand. ( Didn't happen for iron ball that wasn't
chained to hero's leg.)

I thought that this was going to be a one or two line fix but ball
and chain stuff is never that simple.

Fixes #949

doc/fixes3-7-0.txt

@@ -1068,6 +1068,8 @@ if hero's action caused engulfer to expel swallowed hero, it might do so onto
 throwing recoil while levitating could send hero out of shop while carrying
 	unpaid items, triggering sanity check warnings; once outside, taking
 	a step other than back into the shop was treated as a robbery
+if punished and iron ball was cursed and wielded--so welded to hand--falling
+	when doors would drop it instead of keeping it welded
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository

src/ball.c

@@ -22,7 +22,7 @@ static struct breadcrumbs bcpbreadcrumbs = {0}, bcubreadcrumbs = {0};
 void
 ballrelease(boolean showmsg)
 {
-    if (carried(uball)) {
+    if (carried(uball) && !welded(uball)) {
         if (showmsg)
             pline("Startled, you drop the iron ball.");
         if (uwep == uball)
@@ -44,6 +44,9 @@ ballfall(void)
 {
     boolean gets_hit;
 
+    if (uball && carried(uball) && welded(uball))
+        return;
+
     gets_hit = (((uball->ox != u.ux) || (uball->oy != u.uy))
                 && ((uwep == uball) ? FALSE : (boolean) rn2(5)));
     ballrelease(TRUE);
@@ -996,7 +999,7 @@ drag_down(void)
      */
     forward = carried(uball) && (uwep == uball || !uwep || !rn2(3));
 
-    if (carried(uball))
+    if (carried(uball) && !welded(uball))
         You("lose your grip on the iron ball.");
 
     cls();  /* previous level is still displayed although you

src/do.c

@@ -595,6 +595,19 @@ canletgo(struct obj *obj, const char *word)
             Norep("You cannot %s %s you are wearing.", word, something);
         return FALSE;
     }
+    if (obj == uwep && welded(uwep)) {
+        /* no weldmsg(), so uwep->bknown might become set silently
+           if word is "" */
+        if (*word) {
+            const char *hand = body_part(HAND);
+
+            if (bimanual(uwep))
+                hand = makeplural(hand);
+            Norep("You cannot %s %s welded to your %s.", word, something,
+                  hand);
+        }
+        return FALSE;
+    }
     if (obj->otyp == LOADSTONE && obj->cursed) {
         /* getobj() kludge sets corpsenm to user's specified count
            when refusing to split a stack of cursed loadstones */
@@ -1612,7 +1625,8 @@ goto_level(
                 You("fall down the %s.", ga.at_ladder ? "ladder" : "stairs");
                 if (Punished) {
                     drag_down();
-                    ballrelease(FALSE);
+                    if (!welded(uball))
+                        ballrelease(FALSE);
                 }
                 /* falling off steed has its own losehp() call */
                 if (u.usteed)
@@ -1632,7 +1646,7 @@ goto_level(
     } else { /* trap door or level_tele or In_endgame */
         u_on_rndspot((up ? 1 : 0) | (was_in_W_tower ? 2 : 0));
         if (falling) {
-            if (Punished)
+            if (Punished && !welded(uball))
                 ballfall();
             selftouch("Falling, you");
             do_fall_dmg = TRUE;

src/wield.c

@@ -1030,11 +1030,15 @@ void
 weldmsg(struct obj *obj)
 {
     long savewornmask;
+    const char *hand = body_part(HAND);
 
+    if (bimanual(obj))
+        hand = makeplural(hand);
     savewornmask = obj->owornmask;
-    pline("%s welded to your %s!", Yobjnam2(obj, "are"),
+    obj->owornmask = 0L; /* suppress doname()'s "(weapon in hand)";
-          bimanual(obj) ? (const char *) makeplural(body_part(HAND))
+                          * Yobjnam2() doesn't actually need this because
-                        : body_part(HAND));
+                          * it is based on xname() rather than doname() */
+    pline("%s welded to your %s!", Yobjnam2(obj, "are"), hand);
     obj->owornmask = savewornmask;
 }