redo nowrap_add()

Yahoo!'s mailer delivered the report about nowrap_add() to my spam
folder, apparently because it thinks that the signature attachments
"may contain harmful content".  :-(

nowrap_add() checks for signed overflow after the fact, so after
undefined behavior if that happens.

This rewrites nowrap_add() and moves it from end.c to integer.h.

I haven't generated any values big enough to exercise it, but the
algorithm is straightforward so I'll take it on faith.

include/integer.h

@@ -1,4 +1,4 @@
-/* NetHack 3.7	integer.h	$NHDT-Date: 1717967331 2024/06/09 21:08:51 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.12 $ */
+/* NetHack 3.7	integer.h	$NHDT-Date: 1720397754 2024/07/08 00:15:54 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.13 $ */
 /*      Copyright (c) 2016 by Michael Allison          */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -110,4 +110,9 @@ typedef uint64_t uint64;
      ? (L) * 10L + (D)                                          \
      : -1L)
 
+/* add a and b, return max long value if overflow would have occurred;
+   assumes that both a and b are non-negative; caller should apply
+   cast(s) to (long) in the arguments if any are needed */
+#define nowrap_add(a,b) ((a) <= (LONG_MAX - (b)) ? ((a) + (b)) : LONG_MAX)
+
 #endif /* INTEGER_H */

src/botl.c

@@ -1,4 +1,4 @@
-/* NetHack 3.7	botl.c	$NHDT-Date: 1694893342 2023/09/16 19:42:22 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.239 $ */
+/* NetHack 3.7	botl.c	$NHDT-Date: 1720397739 2024/07/08 00:15:39 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.264 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Michael Allison, 2006. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -423,17 +423,20 @@ long
 botl_score(void)
 {
     long deepest = deepest_lev_reached(FALSE);
-    long utotal;
+    long umoney, depthbonus;
 
     /* hidden_gold(False): only gold in containers whose contents are known */
-    utotal = money_cnt(gi.invent) + hidden_gold(FALSE);
+    umoney = money_cnt(gi.invent) + hidden_gold(FALSE);
-    if ((utotal -= u.umoney0) < 0L)
+    /* don't include initial gold; don't impose penalty if its all gone */
-        utotal = 0L;
+    if ((umoney -= u.umoney0) < 0L)
-    utotal += u.urexp + (50 * (deepest - 1))
+        umoney = 0L;
-          + (deepest > 30 ? 10000 : deepest > 20 ? 1000 * (deepest - 20) : 0);
+    depthbonus = 50 * (deepest - 1)
-    if (utotal < u.urexp)
+                 + (deepest > 30) ? 10000
-        utotal = LONG_MAX; /* wrap around */
+                   : (deepest > 20) ? 1000 * (deepest - 20)
-    return utotal;
+                     : 0;
+    /* neither umoney nor depthbonus can grow unusually big (gold due to
+       weight); u.urexp might */
+    return nowrap_add(u.urexp, umoney + depthbonus);
 }
 #endif /* SCORE_ON_BOTL */
 

src/end.c

@@ -1,4 +1,4 @@
-/* NetHack 3.7	end.c	$NHDT-Date: 1711735821 2024/03/29 18:10:21 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.313 $ */
+/* NetHack 3.7	end.c	$NHDT-Date: 1720397752 2024/07/08 00:15:52 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.315 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2012. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -15,10 +15,6 @@
 #endif
 #include "dlb.h"
 
-
-/* add b to long a, convert wraparound to max value */
-#define nowrap_add(a, b) (a = ((a + b) < 0 ? LONG_MAX : (a + b)))
-
 #ifndef NO_SIGNAL
 staticfn void done_intr(int);
 # if defined(UNIX) || defined(VMS) || defined(__EMX__)