From 4d6e3326bba24ad259eae0ea06a12790560a45b4 Mon Sep 17 00:00:00 2001
From: nhmall <nhmall@nethack.org>
Date: Fri, 23 Nov 2018 22:17:09 -0500
Subject: [PATCH] Revert "Instance variable work."

This reverts commit 14bf74c8629fe1731cb0dc72afa263256980f89f.
---
 include/decl.h |  5 -----
 src/decl.c     |  5 -----
 src/save.c     | 24 ++++++++++++++----------
 3 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/include/decl.h b/include/decl.h
index e8a8dfab5..e0597efe3 100644
--- a/include/decl.h
+++ b/include/decl.h
@@ -460,11 +460,6 @@ struct instance_variables {
     boolean m_using; /* kludge to use mondided instead of killed */
     /* pickup.c */
     int oldcap; /* last encumberance */
-    /* save.c */
-    boolean havestate;
-    unsigned ustuck_id; /* need to preserve during save */
-    unsigned usteed_id; /* need to preserve during save */
-
     /* trap.c */
     int force_mintrap; /* mintrap() should take a flags argument, but for time
                           being we use this */
diff --git a/src/decl.c b/src/decl.c
index c517edaa5..a6c651965 100644
--- a/src/decl.c
+++ b/src/decl.c
@@ -344,10 +344,6 @@ const struct instance_variables iv_init = {
     FALSE, /* m_using */
     /* pickup.c */
     0,  /* oldcap */
-    /* save.c */
-    TRUE, /* havestate*/
-    0, /* ustuck_id */
-    0, /* usteed_id */
     /* trap.c */
     0, /* force_mintrap */
     /* u_init.c */
@@ -374,7 +370,6 @@ instance_variable_init()
     iv = iv_init;
 
     nhassert(iv_init.magic == IVMAGIC);
-    nhassert(iv.havestate == TRUE);
 
     sfcap = default_sfinfo;
     sfrestinfo = default_sfinfo;
diff --git a/src/save.c b/src/save.c
index de2c99b74..bca03c49e 100644
--- a/src/save.c
+++ b/src/save.c
@@ -71,6 +71,9 @@ static struct save_procs {
 #define HUP
 #endif
 
+/* need to preserve these during save to avoid accessing freed memory */
+static unsigned ustuck_id = 0, usteed_id = 0;
+
 int
 dosave()
 {
@@ -210,8 +213,8 @@ dosave0()
     store_version(fd);
     store_savefileinfo(fd);
     store_plname_in_file(fd);
-    iv.ustuck_id = (u.ustuck ? u.ustuck->m_id : 0);
-    iv.usteed_id = (u.usteed ? u.usteed->m_id : 0);
+    ustuck_id = (u.ustuck ? u.ustuck->m_id : 0);
+    usteed_id = (u.usteed ? u.usteed->m_id : 0);
     savelev(fd, ledger_no(&u.uz), WRITE_SAVE | FREE_SAVE);
     savegamestate(fd, WRITE_SAVE | FREE_SAVE);
 
@@ -333,10 +336,10 @@ register int fd, mode;
            sizeof(struct spell) * (MAXSPELL + 1));
     save_artifacts(fd);
     save_oracles(fd, mode);
-    if (iv.ustuck_id)
-        bwrite(fd, (genericptr_t) &iv.ustuck_id, sizeof iv.ustuck_id);
-    if (iv.usteed_id)
-        bwrite(fd, (genericptr_t) &iv.usteed_id, sizeof iv.usteed_id);
+    if (ustuck_id)
+        bwrite(fd, (genericptr_t) &ustuck_id, sizeof ustuck_id);
+    if (usteed_id)
+        bwrite(fd, (genericptr_t) &usteed_id, sizeof usteed_id);
     bwrite(fd, (genericptr_t) pl_character, sizeof pl_character);
     bwrite(fd, (genericptr_t) pl_fruit, sizeof pl_fruit);
     savefruitchn(fd, mode);
@@ -366,6 +369,7 @@ void
 savestateinlock()
 {
     int fd, hpid;
+    static boolean havestate = TRUE;
     char whynot[BUFSZ];
 
     /* When checkpointing is on, the full state needs to be written
@@ -379,7 +383,7 @@ savestateinlock()
      * noop pid rewriting will take place on the first "checkpoint" after
      * the game is started or restored, if checkpointing is off.
      */
-    if (flags.ins_chkpt || iv.havestate) {
+    if (flags.ins_chkpt || havestate) {
         /* save the rest of the current game state in the lock file,
          * following the original int pid, the current level number,
          * and the current savefile name, which should not be subject
@@ -417,13 +421,13 @@ savestateinlock()
             store_savefileinfo(fd);
             store_plname_in_file(fd);
 
-            iv.ustuck_id = (u.ustuck ? u.ustuck->m_id : 0);
-            iv.usteed_id = (u.usteed ? u.usteed->m_id : 0);
+            ustuck_id = (u.ustuck ? u.ustuck->m_id : 0);
+            usteed_id = (u.usteed ? u.usteed->m_id : 0);
             savegamestate(fd, WRITE_SAVE);
         }
         bclose(fd);
     }
-    iv.havestate = flags.ins_chkpt;
+    havestate = flags.ins_chkpt;
 }
 #endif