SPDXify the code.

[open-adventure.git] / saveresume.c

diff --git a/saveresume.c b/saveresume.c
index f1d52d458423cedd5e01e7bff1dcfc4c45288eff..b03a6215c5c6d11b862add5700eb91a39e5d551e 100644 (file)
--- a/saveresume.c
+++ b/saveresume.c
@@ -1,3 +1,14 @@
+/*
+ * Saving and resuming.
+ *
+ * (ESR) This replaces  a bunch of particularly nasty FORTRAN-derived code;
+ * see the history.adoc file in the source distribution for discussion.
+ *
+ * Copyright (c) 1977, 2005 by Will Crowther and Don Woods
+ * Copyright (c) 2017 by Eric S. Raymond
+ * SPDX-License-Identifier: BSD-2-clause
+ */
+
 #include <stdlib.h>
 #include <string.h>
 #include <editline/readline.h>
@@ -7,11 +18,6 @@
 #include "advent.h"
 #include "dungeon.h"
 
-/*
- * (ESR) This replaces  a bunch of particularly nasty FORTRAN-derived code;
- * see the history.adoc file in the source distribution for discussion.
- */
-
 #define VRSION 28      /* bump on save format change */
 
 /*
@@ -145,13 +151,18 @@ bool is_valid(struct game_t* valgame)
         valgame->lcg_x %= LCG_M;
     }
 
+    /* Check for RNG underflow. Transpose */
+    if (valgame->lcg_x < LCG_M) {
+        valgame->lcg_x = LCG_M + (valgame->lcg_x % LCG_M);
+    }
+
     /*  Bounds check for locations */
     if ( valgame->chloc  < -1 || valgame->chloc  > NLOCATIONS ||
          valgame->chloc2 < -1 || valgame->chloc2 > NLOCATIONS ||
-         valgame->loc    < -1 || valgame->loc    > NLOCATIONS ||
-         valgame->newloc < -1 || valgame->newloc > NLOCATIONS ||
-         valgame->oldloc < -1 || valgame->oldloc > NLOCATIONS ||
-         valgame->oldlc2 < -1 || valgame->oldlc2 > NLOCATIONS) {
+         valgame->loc    <  0 || valgame->loc    > NLOCATIONS ||
+         valgame->newloc <  0 || valgame->newloc > NLOCATIONS ||
+         valgame->oldloc <  0 || valgame->oldloc > NLOCATIONS ||
+         valgame->oldlc2 <  0 || valgame->oldlc2 > NLOCATIONS) {
         return false;
     }
     /*  Bounds check for location arrays */