make #migratemons unconditional

Make #migratemons command be unconditional.  The show existing
ones part is now always present.  Compile-time DEBUG_MIGRATING_MONS
controls whether the create N new migrators part is available.

Fix creating new ones from the Castle level.  It knew how to find
the next level (Valley) but wouldn't send monsters there because of
its Is_botlevel() check.

dat/wizhelp

@@ -11,6 +11,7 @@ Debug-Mode Quick Reference:
 
 #levelchange    == set hero's experience level
 #lightsources   == show mobile light sources
+#migratemons    == show migrating monsters; optionally create some
 #panic          == panic test (warning: current game will be terminated)
 #polyself       == polymorph self
 #stats          == show memory statistics

src/cmd.c

@@ -129,9 +129,7 @@ static int wiz_intrinsic(void);
 static int wiz_show_wmodes(void);
 static int wiz_show_stats(void);
 static int wiz_rumor_check(void);
-#ifdef DEBUG_MIGRATING_MONS
 static int wiz_migrate_mons(void);
-#endif
 
 static void makemap_unmakemon(struct monst *, boolean);
 static void makemap_remove_mons(void);
@@ -162,6 +160,8 @@ static char readchar_core(coordxy *, coordxy *, int *);
 static char *parse(void);
 static void show_direction_keys(winid, char, boolean);
 static boolean help_dir(char, uchar, const char *);
+static int QSORTCALLBACK migrsort_cmp(const genericptr, const genericptr);
+static void list_migrating_mons(d_level *);
 
 static void handler_rebind_keys_add(boolean);
 static boolean bind_key_fn(uchar, int (*)(void));
@@ -2564,10 +2564,13 @@ struct ext_func_tab extcmdlist[] = {
               dolook, IFBURIED, NULL },
     { M('l'), "loot", "loot a box on the floor",
               doloot, AUTOCOMPLETE | CMD_M_PREFIX, NULL },
-#ifdef DEBUG_MIGRATING_MONS
+    { '\0',   "migratemons",
-    { '\0',   "migratemons", "migrate N random monsters",
+#ifdef DEBUG_MIGRATING_MONSTERS
-              wiz_migrate_mons, IFBURIED | AUTOCOMPLETE | WIZMODECMD, NULL },
+              "show migrating monsters and migrate N random ones",
+#else
+              "show migrating monsters",
 #endif
+              wiz_migrate_mons, IFBURIED | AUTOCOMPLETE | WIZMODECMD, NULL },
     { M('m'), "monster", "use monster's special ability",
               domonability, IFBURIED | AUTOCOMPLETE, NULL },
     { M('n'), "name", "same as call; name a monster or object or object type",
@@ -4018,22 +4021,24 @@ sanity_check(void)
     trap_sanity_check();
 }
 
-#ifdef DEBUG_MIGRATING_MONS
+/* qsort() comparison routine for use in list_migrating_mons() */
-static int QSORTCALLBACK migrsort_cmp(const genericptr, const genericptr);
-static void list_migrating_mons(d_level *);
-
 static int QSORTCALLBACK
 migrsort_cmp(const genericptr vptr1, const genericptr vptr2)
 {
     const struct monst *m1 = *(const struct monst **) vptr1,
                        *m2 = *(const struct monst **) vptr2;
-    int d1 = m1->mux, l1 = m1->muy, d2 = m2->mux, l2 = m2->muy;
+    int d1 = (int) m1->mux, l1 = (int) m1->muy,
+        d2 = (int) m2->mux, l2 = (int) m2->muy;
 
-    if (d1 < d2 || (d1 == d2 && l1 < l2))
+    /* if different branches, sort by dungeon number */
-        return -1;
+    if (d1 != d2)
-    if (d1 > d2 || (d1 == d2 && l1 > l2))
+        return d1 - d2;
-        return 1;
+    /* within same branch, sort by level number */
-    return 0; /* tie => same destination */
+    if (l1 != l2)
+        return l1 - l2;
+    /* same destination level:  use a tie-breaker to force stable sort;
+       monst->m_id is unsigned so we need more than just simple subtraction */
+    return (m1->m_id < m2->m_id) ? -1 : (m1->m_id > m2->m_id);
 }
 
 /* called by #migratemons; might turn it into separate wizard mode command */
@@ -4096,8 +4101,8 @@ list_migrating_mons(
             putstr(win, 0, "");
             /* collect the migrating monsters into an array; for 'o' and 'a'
                where multiple destination levels might be present, sort by
-               the destination; no sorting needed for 'c' and 'n' but it's
+               the destination; 'c' and 'n' don't need to be sorted but we
-               simpler to use the array than to have separate traversal */
+               do that anyway to get the same tie-breaker as 'o' and 'a' */
             marray = (struct monst **) alloc((n + 1) * sizeof *marray);
             n = 0;
             for (mtmp = g.migrating_mons; mtmp; mtmp = mtmp->nmon) {
@@ -4114,8 +4119,8 @@ list_migrating_mons(
                 if (showit)
                     marray[n++] = mtmp;;
             }
-            marray[n] = (struct monst *) 0;
+            marray[n] = (struct monst *) 0; /* mark end for traversal loop */
-            if (n > 1 && c != 'c' && c != 'n')
+            if (n > 1)
                 qsort((genericptr_t) marray, (size_t) n, sizeof *marray,
                       migrsort_cmp); /* sort elements [0] through [n-1] */
             for (n = 0; (mtmp = marray[n]) != 0; ++n) {
@@ -4144,28 +4149,43 @@ list_migrating_mons(
     }
 }
 
+/* #migratemons command */
 static int
 wiz_migrate_mons(void)
 {
+#ifdef DEBUG_MIGRATING_MONS
     int mcount;
-    char inbuf[BUFSZ] = DUMMY;
+    char inbuf[BUFSZ];
     struct permonst *ptr;
     struct monst *mtmp;
+#endif
     d_level tolevel;
 
     if (Is_stronghold(&u.uz))
         assign_level(&tolevel, &valley_level);
-    else
+    else if (!Is_botlevel(&u.uz))
         get_level(&tolevel, depth(&u.uz) + 1);
+    else
+        tolevel.dnum = 0, tolevel.dlevel = 0;
 
     list_migrating_mons(&tolevel);
 
-    getlin("How many random monsters to migrate to next level? [0]", inbuf);
+#ifdef DEBUG_MIGRATING_MONS
+    inbuf[0] = '\033', inbuf[1] = '\0';
+    if (tolevel.dnum || tolevel.dlevel)
+        getlin("How many random monsters to migrate to next level? [0]",
+               inbuf);
+    else
+        pline("Can't get there from here.");
     if (*inbuf == '\033')
         return ECMD_OK;
+
     mcount = atoi(inbuf);
-    if (mcount < 0 || mcount > (COLNO * ROWNO) || Is_botlevel(&u.uz))
+    if (mcount < 1)
-        return ECMD_OK;
+        mcount = 0;
+    else if (mcount > ((COLNO - 1) * ROWNO))
+        mcount = (COLNO - 1) * ROWNO;
+
     while (mcount > 0) {
         ptr = rndmonst();
         mtmp = makemon(ptr, 0, 0, MM_NOMSG);
@@ -4174,9 +4194,9 @@ wiz_migrate_mons(void)
                              (coord *) 0);
         mcount--;
     }
+#endif /* DEBUG_MIGRATING_MONS */
     return ECMD_OK;
 }
-#endif /* DEBUG_MIGRATING_MONS */
 
 static struct {
     int nhkf;