From 8672807a5ec8fbe1834a20991a3fe390651e0405 Mon Sep 17 00:00:00 2001
From: nhmall <nhmall@nethack.org>
Date: Fri, 14 Feb 2025 19:30:34 -0500
Subject: [PATCH] cmp_init_mongen_order() qsort comparison function tweaks

The array was ending up ordered the same on different qsort
implementations.

This incorporates the mlet value into the sort value for comparison.
That guarantees that everything stays ordered by mlet, followed by
difficulty (and would even if something ever got misplaced in
monsters.h). It means the "they are equal" zero return for differing
mlet values is not required, and has been removed.

This removes the "they are equal" zero returns for G_NOGEN | G_UNIQ
monsters, so they will still get sorted rather than left at the
whatever array element they happened to be at (which I don't think
should be an issue?).
---
 src/makemon.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/src/makemon.c b/src/makemon.c
index f365d643f..77ce688eb 100644
--- a/src/makemon.c
+++ b/src/makemon.c
@@ -1752,16 +1752,21 @@ static boolean mongen_order_init = FALSE;
 staticfn int QSORTCALLBACK
 cmp_init_mongen_order(const void *p1, const void *p2)
 {
-    const int *pi1 = p1;
-    const int *pi2 = p2;
-    int i1 = *pi1, i2 = *pi2;
+    int i1 = *((int *) p1), i2 = *((int *) p2);
+ #if 0
+    /* This will cause these to be moved last in the mlet sort order */
+    int offset1 = ((mons[i1].geno & (G_NOGEN | G_UNIQ)) != 0) ? 99 : 0,
+        offset2 = ((mons[i2].geno & (G_NOGEN | G_UNIQ)) != 0) ? 99 : 0;
+#else
+    int offset1 = 0, offset2 = 0;
+#endif
 
-    if (((mons[i1].geno & (G_NOGEN|G_UNIQ)) != 0)
-        || ((mons[i2].geno & (G_NOGEN|G_UNIQ)) != 0))
-        return 0;
-    if (mons[i1].mlet != mons[i2].mlet)
-        return 0;
-    return (int)(mons[i1].difficulty - mons[i2].difficulty);
+    /* incorporate the mlet into the sort values for comparison */
+    int difficulty1 =
+            ((int) mons[i1].difficulty + offset1 | ((int) mons[i1].mlet << 8)),
+        difficulty2 =
+            ((int) mons[i2].difficulty + offset2 | ((int) mons[i2].mlet << 8));
+    return difficulty1 - difficulty2;
 }
 
 /* check that monsters are in correct difficulty order for mkclass() */
@@ -1797,13 +1802,13 @@ init_mongen_order(void)
         return;
 
     mongen_order_init = TRUE;
-    for (i = LOW_PM; i <= SPECIAL_PM; i++)
+    for (i = LOW_PM; i <= NUMMONS; i++)
         mongen_order[i] = i;
 
 #if (NH_DEVEL_STATUS != NH_STATUS_RELEASED)
     check_mongen_order();
 #endif
-    qsort((genericptr_t) mongen_order, NUMMONS, sizeof(int), cmp_init_mongen_order);
+    qsort((genericptr_t) mongen_order, SPECIAL_PM, sizeof(int), cmp_init_mongen_order);
 #if (NH_DEVEL_STATUS != NH_STATUS_RELEASED)
     check_mongen_order();
 #endif