Add a new themed room: "Twin business"

This themed room boasts two shops, a weapons and an armor store,
that can generate in a number of different configurations.

Makes the random corridor joining routine obey unjoined areas.

Fixes a bug in shopkeeper naming routine, where multiple shops
of the same type on the same level might reuse the shopkeeper name.

This is modified and consolidated commit from xNetHack by
copperwater <aosdict@gmail.com>.

src/mklev.c

@@ -35,6 +35,7 @@ static void FDECL(do_room_or_subroom, (struct mkroom *, int, int,
                                            int, int, BOOLEAN_P,
                                            SCHAR_P, BOOLEAN_P, BOOLEAN_P));
 static void NDECL(makerooms);
+static boolean FDECL(door_into_nonjoined, (XCHAR_P, XCHAR_P));
 static void FDECL(finddpos, (coord *, XCHAR_P, XCHAR_P,
                                  XCHAR_P, XCHAR_P));
 static void FDECL(mkinvpos, (XCHAR_P, XCHAR_P, int));
@@ -68,6 +69,33 @@ const genericptr vy;
 #endif /* LINT */
 }
 
+/* Return TRUE if a door placed at (x, y) which otherwise passes okdoor() checks
+ * would be connecting into an area that was declared as joined = 0.
+ * Checking for this in finddpos() enables us to have rooms with sub-areas (such
+ * as shops) that will never randomly generate unwanted doors in order to
+ * connect them up to other areas.
+ */
+static boolean
+door_into_nonjoined(x, y)
+xchar x, y;
+{
+    xchar tx, ty, diridx;
+
+    for (diridx = 0; diridx <= 6; diridx += 2) {
+        tx = x + xdir[diridx];
+        ty = y + ydir[diridx];
+        if (!isok(tx, ty) || IS_ROCK(levl[tx][ty].typ))
+            continue;
+
+        /* Is this connecting to a room that doesn't want joining? */
+        if (levl[tx][ty].roomno >= ROOMOFFSET &&
+            !g.rooms[levl[tx][ty].roomno - ROOMOFFSET].needjoining) {
+            return TRUE;
+        }
+    }
+    return FALSE;
+}
+
 static void
 finddpos(cc, xl, yl, xh, yh)
 coord *cc;
@@ -77,12 +105,12 @@ xchar xl, yl, xh, yh;
 
     x = rn1(xh - xl + 1, xl);
     y = rn1(yh - yl + 1, yl);
-    if (okdoor(x, y))
+    if (okdoor(x, y) && !door_into_nonjoined(x, y))
         goto gotit;
 
     for (x = xl; x <= xh; x++)
         for (y = yl; y <= yh; y++)
-            if (okdoor(x, y))
+            if (okdoor(x, y) && !door_into_nonjoined(x, y))
                 goto gotit;
 
     for (x = xl; x <= xh; x++)
@@ -92,6 +120,8 @@ xchar xl, yl, xh, yh;
     /* cannot find something reasonable -- strange */
     x = xl;
     y = yh;
+    impossible("finddpos: couldn't find door pos within (%d,%d,%d,%d)",
+               xl, yl, xh, yh);
  gotit:
     cc->x = x;
     cc->y = y;

src/shknam.c

@@ -495,7 +495,7 @@ const char *const *nlp;
     int i, trycnt, names_avail;
     const char *shname = 0;
     struct monst *mtmp;
-    int name_wanted;
+    int name_wanted = shk->m_id;
     s_level *sptr;
 
     if (nlp == shklight && In_mines(&u.uz)
@@ -510,7 +510,7 @@ const char *const *nlp;
            use ledger_no rather than depth to keep minetown distinct. */
         int nseed = (int) ((long) ubirthday / 257L);
 
-        name_wanted = ledger_no(&u.uz) + (nseed % 13) - (nseed % 5);
+        name_wanted += ledger_no(&u.uz) + (nseed % 13) - (nseed % 5);
         if (name_wanted < 0)
             name_wanted += (13 + 5);
         shk->female = name_wanted & 1;
@@ -518,6 +518,8 @@ const char *const *nlp;
         for (names_avail = 0; nlp[names_avail]; names_avail++)
             continue;
 
+        name_wanted = name_wanted % names_avail;
+
         for (trycnt = 0; trycnt < 50; trycnt++) {
             if (nlp == shktools) {
                 shname = shktools[rn2(names_avail)];
@@ -545,6 +547,7 @@ const char *const *nlp;
                     continue;
                 if (strcmp(ESHK(mtmp)->shknam, shname))
                     continue;
+                name_wanted = names_avail; /* try a random name */
                 break;
             }
             if (!mtmp)