update: Use a scratch sctstr for production simulation

If player->simulation, produce_sect() must not change game state,
except for sct_updated.  To avoid changing sectors, it copies each
sector's sct_item[] to a scratch buffer, and tracks new designation,
efficiency and available work in local variables.

Copy the complete sector to a scratch buffer instead.  This is safer,
and will permit code simplifications.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>

diff --git a/src/lib/update/sect.c b/src/lib/update/sect.c
index 7d174358e87bd4a0116e372cf896346f00aad87d..fbfac5cee43b3ff334464aaf1b1b0312892bfb56 100644 (file)
--- a/src/lib/update/sect.c
+++ b/src/lib/update/sect.c
@@ -244,9 +244,7 @@ decay_fallout(struct sctstr *sp, int etus)
 void
 produce_sect(struct natstr *np, int etu, struct bp *bp, int p_sect[][2])
 {
-    struct sctstr *sp;
-    short buf[I_MAX + 1];
-    short *vec;
+    struct sctstr *sp, scratch_sect;
     int work, cost, ecost, pcost;
     int n, desig, neweff, amount;
 
@@ -268,16 +266,15 @@ produce_sect(struct natstr *np, int etu, struct bp *bp, int p_sect[][2])
 
        if (player->simulation) {
            /* work on a copy, which will be discarded */
-           memcpy(buf, sp->sct_item, sizeof(buf));
-           vec = buf;
-       } else
-           vec = sp->sct_item;
+           scratch_sect = *sp;
+           sp = &scratch_sect;
+       }
 
        /* If everybody is dead, the sector reverts to unowned.
         * This is also checked at the end of the production in
         * they all starved or were plagued off.
         */
-       if (vec[I_CIVIL] == 0 && vec[I_MILIT] == 0 &&
+       if (sp->sct_item[I_CIVIL] == 0 && sp->sct_item[I_MILIT] == 0 &&
            !has_units(sp->sct_x, sp->sct_y, sp->sct_own)) {
            if (!player->simulation) {
                makelost(EF_SECTOR, sp->sct_own, 0, sp->sct_x, sp->sct_y);
@@ -290,8 +287,8 @@ produce_sect(struct natstr *np, int etu, struct bp *bp, int p_sect[][2])
        sp->sct_updated = 1;
        work = 0;
 
-       do_feed(sp, np, vec, &work, etu);
-       bp_put_items(bp, sp, vec);
+       do_feed(sp, np, sp->sct_item, &work, etu);
+       bp_put_items(bp, sp, sp->sct_item);
 
        if (sp->sct_off || np->nat_money < 0)
            continue;
@@ -312,8 +309,8 @@ produce_sect(struct natstr *np, int etu, struct bp *bp, int p_sect[][2])
 
        if ((sp->sct_effic < 100 || sp->sct_type != sp->sct_newtype) &&
            np->nat_money >= 0) {
-           neweff = upd_buildeff(sp, &work, vec, &desig, &cost);
-           bp_put_items(bp, sp, vec);
+           neweff = upd_buildeff(sp, &work, sp->sct_item, &desig, &cost);
+           bp_put_items(bp, sp, sp->sct_item);
            p_sect[SCT_EFFIC][0]++;
            p_sect[SCT_EFFIC][1] += cost;
            if (!player->simulation) {
@@ -325,11 +322,11 @@ produce_sect(struct natstr *np, int etu, struct bp *bp, int p_sect[][2])
 
        if (desig == SCT_ENLIST && neweff >= 60 &&
            sp->sct_own == sp->sct_oldown) {
-           p_sect[desig][0] += enlist(vec, etu, &ecost);
+           p_sect[desig][0] += enlist(sp->sct_item, etu, &ecost);
            p_sect[desig][1] += ecost;
            if (!player->simulation)
                np->nat_money -= ecost;
-           bp_put_items(bp, sp, vec);
+           bp_put_items(bp, sp, sp->sct_item);
        }
 
        /*
@@ -338,9 +335,9 @@ produce_sect(struct natstr *np, int etu, struct bp *bp, int p_sect[][2])
 
        if (neweff >= 60) {
            if (np->nat_money >= 0 && dchr[desig].d_prd >= 0)
-               work -= produce(np, sp, vec, work, desig, neweff,
+               work -= produce(np, sp, sp->sct_item, work, desig, neweff,
                                &pcost, &amount);
-           bp_put_items(bp, sp, vec);
+           bp_put_items(bp, sp, sp->sct_item);
        }
 
        bp_put_avail(bp, sp, work);