do not use unit.display directly, use getter/setter instead.

src/kernel/save.c

@@ -440,12 +440,12 @@ unit *read_unit(gamedata *data)
     if (unicode_utf8_trim(obuf)!=0) {
 		log_warning("trim unit %s name to '%s'", itoa36(u->no), obuf);
 	}
-    u->_name = obuf[0] ? str_strdup(obuf) : 0;
+    unit_setname(u, obuf[0] ? obuf : NULL);
     READ_STR(data->store, obuf, sizeof(obuf));
     if (unicode_utf8_trim(obuf)!=0) {
         log_warning("trim unit %s info to '%s'", itoa36(u->no), obuf);
     }
-    u->display = obuf[0] ? str_strdup(obuf) : 0;
+    unit_setinfo(u, obuf[0] ? obuf : NULL);
     READ_INT(data->store, &number);
     set_number(u, number);
 
@@ -544,6 +544,7 @@ unit *read_unit(gamedata *data)
 
 void write_unit(gamedata *data, const unit * u)
 {
+    const char *str;
     order *ord;
     int p = 0;
     unsigned int flags = u->flags & UFL_SAVEMASK;
@@ -553,7 +554,8 @@ void write_unit(gamedata *data, const unit * u)
     assert(u->faction->_alive);
     write_faction_reference(u->faction, data->store);
     WRITE_STR(data->store, u->_name);
-    WRITE_STR(data->store, u->display ? u->display : "");
+    str = unit_getinfo(u);
+    WRITE_STR(data->store, str ? str : "");
     WRITE_INT(data->store, u->number);
     WRITE_INT(data->store, u->age);
     WRITE_TOK(data->store, u_race(u)->_name);

src/kernel/unit.c

@@ -474,8 +474,8 @@ attrib_type at_private = {
 
 const char *u_description(const unit * u, const struct locale *lang)
 {
-    if (u->display && u->display[0]) {
-        return u->display;
+    if (u->_display && u->_display[0]) {
+        return u->_display;
     }
     else {
         char zText[64];
@@ -1293,7 +1293,7 @@ void free_unit(unit * u)
 {
     assert(!u->region);
     free(u->_name);
-    free(u->display);
+    free(u->_display);
     free_order(u->thisorder);
     free_orders(&u->orders);
     if (u->skills)
@@ -1522,16 +1522,16 @@ void unit_setname(unit * u, const char *name)
 
 const char *unit_getinfo(const unit * u)
 {
-    return (const char *)u->display;
+    return (const char *)u->_display;
 }
 
 void unit_setinfo(unit * u, const char *info)
 {
-    free(u->display);
+    free(u->_display);
     if (info)
-        u->display = str_strdup(info);
+        u->_display = str_strdup(info);
     else
-        u->display = NULL;
+        u->_display = NULL;
 }
 
 int unit_getid(const unit * u)

src/kernel/unit.h

@@ -89,7 +89,7 @@ extern "C" {
         int no;                     /* id */
         int hp;
         char *_name;
-        char *display;
+        char *_display;
         struct faction *faction;
         struct building *building;
         struct ship *ship;

src/kernel/unit.test.c

@@ -397,14 +397,13 @@ static void test_unit_description(CuTest *tc) {
     rc = test_create_race("hodor");
     u = test_create_unit(test_create_faction(rc), test_create_region(0, 0, NULL));
 
-    CuAssertPtrEquals(tc, NULL, u->display);
-    CuAssertStrEquals(tc, 0, u_description(u, lang));
-    u->display = str_strdup("Hodor");
+    CuAssertStrEquals(tc, NULL, unit_getinfo(u));
+    CuAssertStrEquals(tc, NULL, u_description(u, lang));
+    unit_setinfo(u, "Hodor");
     CuAssertStrEquals(tc, "Hodor", u_description(u, NULL));
     CuAssertStrEquals(tc, "Hodor", u_description(u, lang));
 
-    free(u->display);
-    u->display = NULL;
+    unit_setinfo(u, NULL);
     locale_setstring(lang, "describe_hodor", "HODOR");
     CuAssertStrEquals(tc, "HODOR", u_description(u, lang));
 

src/laws.c

@@ -1542,7 +1542,7 @@ int display_cmd(unit * u, struct order *ord)
         break;
 
     case P_UNIT:
-        s = &u->display;
+        unit_setinfo(u, getstrtoken());
         break;
 
     case P_PRIVAT:

src/laws.test.c

@@ -188,12 +188,12 @@ static void test_display_cmd(CuTest *tc) {
 
     ord = create_order(K_DISPLAY, f->locale, "%s Hodor", LOC(f->locale, parameters[P_UNIT]));
     CuAssertIntEquals(tc, 0, display_cmd(u, ord));
-    CuAssertStrEquals(tc, "Hodor", u->display);
+    CuAssertStrEquals(tc, "Hodor", unit_getinfo(u));
     free_order(ord);
 
     ord = create_order(K_DISPLAY, f->locale, LOC(f->locale, parameters[P_UNIT]));
     CuAssertIntEquals(tc, 0, display_cmd(u, ord));
-    CuAssertPtrEquals(tc, NULL, u->display);
+    CuAssertPtrEquals(tc, NULL, (void *)unit_getinfo(u));
     free_order(ord);
 
     ord = create_order(K_DISPLAY, f->locale, "%s Hodor", LOC(f->locale, parameters[P_REGION]));

src/spells/combatspells.c

@@ -1539,12 +1539,7 @@ int sp_undeadhero(struct castorder * co)
 
             /* new units gets some stats from old unit */
 
-            if (du->display) {
-                unit_setinfo(u, du->display);
-            }
-            else {
-                unit_setinfo(u, NULL);
-            }
+            unit_setinfo(u, unit_getinfo(du));
             unit_setstatus(u, du->status);
             setguard(u, false);
             for (ilist = &du->items; *ilist;) {