Change encoding of `not in any group' from space to 0, because that's

friendlier in conditionals:
(army, build_ship, build_land, build_plane, doship, doplane, dounit)
(flee, check_trade, wing, snxtitem_group, takeover_ship)
(takeover_land): Assign 0 instead of space.
(carg, lcarg, pr_ship, pr_plane, pr_land, ldump, land, pdump, plan)
(retr, lretr, sdump, shi, lnd_list, shp_list, ask_olist, att_prompt)
(ask_move_in): Update printing of group.

(takeover_plane): Failed to clear wing.

include/nuke.h

@@ -47,7 +47,7 @@ struct nukstr {
     signed char nuk_effic;	/* unused, always 100% */
     signed char nuk_mobil;	/* unused, always 0 */
     short nuk_tech;		/* nuke's tech level */
-    char nuk_stockpile;		/* group membership, unused, always ' ' */
+    char nuk_stockpile;		/* group membership, unused */
     coord nuk_opx, nuk_opy;	/* Op sector coords, unused */
     short nuk_mission;		/* mission code, unused */
     short nuk_radius;		/* mission radius, unused */

src/lib/commands/army.c

@@ -62,7 +62,7 @@ army(void)
 	return RET_SYN;
     }
     if (c == '~')
-	c = ' ';
+	c = 0;
     if (!snxtitem(&nstr, EF_LAND, player->argp[2]))
 	return RET_SYN;
     count = 0;

src/lib/commands/buil.c

@@ -369,7 +369,7 @@ build_ship(struct sctstr *sp, struct mchrstr *mp, short *vec, int tlev)
     ship.shp_nland = 0;
     ship.shp_nxlight = 0;
     ship.shp_nchoppers = 0;
-    ship.shp_fleet = ' ';
+    ship.shp_fleet = 0;
     memset(ship.shp_item, 0, sizeof(ship.shp_item));
     ship.shp_pstage = PLG_HEALTHY;
     ship.shp_ptime = 0;
@@ -490,7 +490,7 @@ build_land(struct sctstr *sp, struct lchrstr *lp, short *vec, int tlev)
 	land.lnd_mobil = 0;
     }
     land.lnd_uid = nstr.cur;
-    land.lnd_army = ' ';
+    land.lnd_army = 0;
     land.lnd_flags = 0;
     land.lnd_ship = -1;
     land.lnd_land = -1;
@@ -792,7 +792,7 @@ build_plane(struct sctstr *sp, struct plchrstr *pp, short *vec, int tlev)
     plane.pln_radius = 0;
     plane.pln_range = UCHAR_MAX; /* will be adjusted by pln_set_tech() */
     plane.pln_range_max = plane.pln_range;
-    plane.pln_wing = ' ';
+    plane.pln_wing = 0;
     plane.pln_ship = -1;
     plane.pln_land = -1;
     plane.pln_uid = nstr.cur;

src/lib/commands/carg.c

@@ -63,7 +63,7 @@ carg(void)
 	pr("%4d ", ni.cur);
 	pr("%-4.4s ", mchr[(int)ship.shp_type].m_name);
 	prxy("%4d,%-4d ", ship.shp_x, ship.shp_y, player->cnum);
-	pr("%c ", ship.shp_fleet);
+	pr("%1.1s", &ship.shp_fleet);
 	pr("%4d%%", ship.shp_effic);
 	pr("%4d", ship.shp_item[I_CIVIL]);
 	pr("%4d", ship.shp_item[I_MILIT]);
@@ -112,7 +112,7 @@ lcarg(void)
 	pr("%4d ", ni.cur);
 	pr("%-4.4s ", lchr[(int)land.lnd_type].l_name);
 	prxy("%4d,%-4d ", land.lnd_x, land.lnd_y, player->cnum);
-	pr("%c ", land.lnd_army);
+	pr("%1.1s ", &land.lnd_army);
 	pr("%4d%%", land.lnd_effic);
 	pr("%4d", land.lnd_item[I_CIVIL]);
 	pr("%4d", land.lnd_item[I_MILIT]);

src/lib/commands/edit.c

@@ -329,7 +329,7 @@ pr_plane(struct plnstr *plane)
     pr("Efficiency <e>: %d\t", plane->pln_effic);
     pr("Mobility <m>: %d\n", plane->pln_mobil);
     pr("Tech <t>: %d\t\t", plane->pln_tech);
-    pr("Wing <w>: %c\n", plane->pln_wing);
+    pr("Wing <w>: %.1s\n", &plane->pln_wing);
     pr("Range <r>: %d\t\t", plane->pln_range);
     pr("Flags <f>: %d\n", plane->pln_flags);
     pr("Ship <s>: %d\t\t", plane->pln_ship);
@@ -346,7 +346,7 @@ pr_land(struct lndstr *land)
     pr("Efficiency <e>: %d\t", land->lnd_effic);
     pr("Mobility <M>: %d\n", land->lnd_mobil);
     pr("Tech <t>: %d\t\t", land->lnd_tech);
-    pr("Army <a>: %c\n", land->lnd_army);
+    pr("Army <a>: %.1s\n", &land->lnd_army);
     pr("Fortification <F>: %d\t", land->lnd_harden);
     pr("Fuel <B>: %d\n", land->lnd_fuel);
     pr("Land unit <Y>: %d\n", land->lnd_land);
@@ -387,7 +387,7 @@ pr_ship(struct shpstr *ship)
     pr("Tech <T>: %d\t\t\t", ship->shp_tech);
     pr("Efficiency <E>: %d\n", ship->shp_effic);
     pr("Mobility <M>: %d\t\t", ship->shp_mobil);
-    pr("Fleet <F>: %c\n", ship->shp_fleet);
+    pr("Fleet <F>: %.1s\n", &ship->shp_fleet);
     /* could depend on opt_FUEL - but a deity might want to set this
        up before enabling the option */
     pr("Fuel <B>: %d\n", ship->shp_fuel);
@@ -834,7 +834,7 @@ doship(char op, int arg, char *p, struct shpstr *ship)
 	break;
     case 'F':
 	if (p[0] == '~')
-	    ship->shp_fleet = ' ';
+	    ship->shp_fleet = 0;
 	else if (isalpha(p[0]))
 	    ship->shp_fleet = p[0];
 	else {
@@ -948,7 +948,7 @@ dounit(char op, int arg, char *p, struct lndstr *land)
 	break;
     case 'a':
 	if (p[0] == '~')
-	    land->lnd_army = ' ';
+	    land->lnd_army = 0;
 	else if (isalpha(p[0]))
 	    land->lnd_army = p[0];
 	else {
@@ -1079,7 +1079,7 @@ doplane(char op, int arg, char *p, struct plnstr *plane)
 	break;
     case 'w':
 	if (p[0] == '~')
-	    plane->pln_wing = ' ';
+	    plane->pln_wing = 0;
 	else if (isalpha(p[0]))
 	    plane->pln_wing = p[0];
 	else {

src/lib/commands/flee.c

@@ -62,7 +62,7 @@ flee(void)
 	return RET_SYN;
     }
     if (c == '~')
-	c = ' ';
+	c = 0;
     if (!snxtitem(&nstr, EF_SHIP, player->argp[2]))
 	return RET_SYN;
     count = 0;

src/lib/commands/land.c

@@ -77,7 +77,7 @@ land(void)
 	pr("%4d ", ni.cur);
 	pr("%-15.15s", lchr[(int)land.lnd_type].l_name);
 	prxy(" %4d,%-4d", land.lnd_x, land.lnd_y, player->cnum);
-	pr("%c", land.lnd_army);
+	pr("%1.1s", &land.lnd_army);
 	pr("%4d%%", land.lnd_effic);
 	pr("%4d", land.lnd_item[I_MILIT]);
 	pr("%4d", land.lnd_harden);

src/lib/commands/ldump.c

@@ -326,10 +326,7 @@ ldump(void)
 		pr(" %d", yrel(np, land.lnd_y));
 		break;
 	    case 4:
-		if (land.lnd_army == ' ')
+		pr(" %c ", land.lnd_army ? land.lnd_army : '~');
-		    pr(" ~");
-		else
-		    pr(" %c", land.lnd_army);
 		break;
 	    case 5:
 		pr(" %d", land.lnd_effic);

src/lib/commands/pdump.c

@@ -222,10 +222,7 @@ pdump(void)
 		pr(" %d", yrel(natp, plane.pln_y));
 		break;
 	    case 4:
-		if (plane.pln_wing == ' ')
+		pr(" %c ", plane.pln_wing ? plane.pln_wing : '~');
-		    pr(" ~");
-		else
-		    pr(" %c", plane.pln_wing);
 		break;
 	    case 5:
 		pr(" %d", plane.pln_effic);

src/lib/commands/plan.c

@@ -65,9 +65,8 @@ plan(void)
 	    pr("%3d ", plane.pln_own);
 	pr("%4d %-19.19s ", np.cur, plchr[(int)plane.pln_type].pl_name);
 	prxy("%4d,%-4d", plane.pln_x, plane.pln_y, player->cnum);
-	pr(" %c %3d%% %3d %3d %4d %3d  %3d",
+	pr(" %1.1s %3d%% %3d %3d %4d %3d  %3d",
-	   plane.pln_wing, plane.pln_effic,
+	   &plane.pln_wing, plane.pln_effic, plane.pln_mobil,
-	   plane.pln_mobil,
 	   plane.pln_def, plane.pln_tech,
 	   plane.pln_range, plane.pln_harden);
 	if (plane.pln_ship >= 0)

src/lib/commands/retr.c

@@ -160,7 +160,7 @@ retr(void)
 	pr("%4d ", ni.cur);
 	pr("%-16.16s ", mchr[(int)ship.shp_type].m_name);
 	prxy("%4d,%-4d ", ship.shp_x, ship.shp_y, player->cnum);
-	pr("%c", ship.shp_fleet);
+	pr("%1.1s", &ship.shp_fleet);
 	pr(" %-11s", ship.shp_rpath);
 	if (ship.shp_rflags & RET_GROUP)
 	    pr("Yes     ");
@@ -289,7 +289,7 @@ lretr(void)
 	pr("%4d ", ni.cur);
 	pr("%-16.16s ", lchr[(int)land.lnd_type].l_name);
 	prxy("%4d,%-4d ", land.lnd_x, land.lnd_y, player->cnum);
-	pr("%c", land.lnd_army);
+	pr("%1.1s", &land.lnd_army);
 	pr(" %-11s", land.lnd_rpath);
 	if (land.lnd_rflags & RET_GROUP)
 	    pr("Yes      ");

src/lib/commands/sdump.c

@@ -288,10 +288,7 @@ sdump(void)
 		pr(" %d", yrel(np, ship.shp_y));
 		break;
 	    case 4:
-		if (ship.shp_fleet == ' ')
+		pr(" %c ", ship.shp_fleet ? ship.shp_fleet : '~');
-		    pr(" ~");
-		else
-		    pr(" %c", ship.shp_fleet);
 		break;
 	    case 5:
 		pr(" %d", ship.shp_effic);

src/lib/commands/shi.c

@@ -75,7 +75,7 @@ shi(void)
 	pr("%4d ", ni.cur);
 	pr("%-16.16s ", mchr[(int)ship.shp_type].m_name);
 	prxy("%4d,%-4d ", ship.shp_x, ship.shp_y, player->cnum);
-	pr("%c", ship.shp_fleet);
+	pr("%1.1s", &ship.shp_fleet);
 	pr("%4d%%", ship.shp_effic);
 
 	pr("%4d", ship.shp_item[I_CIVIL]);

src/lib/commands/trad.c

@@ -398,7 +398,7 @@ check_trade(void)
 	    tg.pln.pln_own = trade.trd_maxbidder;
 	    makenotlost(EF_PLANE, tg.pln.pln_own, tg.pln.pln_uid,
 			tg.pln.pln_x, tg.pln.pln_y);
-	    tg.pln.pln_wing = ' ';
+	    tg.pln.pln_wing = 0;
 	    /* no cheap version of fly */
 	    if (opt_MOB_ACCESS) {
 		tg.pln.pln_mobil = -(etu_per_update / sect_mob_neg_factor);
@@ -428,7 +428,7 @@ check_trade(void)
 	    tg.lnd.lnd_own = trade.trd_maxbidder;
 	    makenotlost(EF_LAND, tg.lnd.lnd_own, tg.lnd.lnd_uid,
 			tg.lnd.lnd_x, tg.lnd.lnd_y);
-	    tg.lnd.lnd_army = ' ';
+	    tg.lnd.lnd_army = 0;
 	    /* no cheap version of fly */
 	    if (opt_MOB_ACCESS) {
 		tg.lnd.lnd_mobil = -(etu_per_update / sect_mob_neg_factor);

src/lib/commands/wing.c

@@ -60,7 +60,7 @@ wing(void)
 	return RET_SYN;
     }
     if (c == '~')
-	c = ' ';
+	c = 0;
     if (!snxtitem(&nstr, EF_PLANE, player->argp[2]))
 	return RET_SYN;
     count = 0;

src/lib/subs/attsub.c

@@ -921,7 +921,7 @@ att_prompt(char *prompt, char army)
     char buf[1024];
     char *p;
 
-    if (army == ' ')
+    if (!army)
 	army = '~';
     for (;;) {
 	p = getstring(prompt, buf);
@@ -1051,7 +1051,7 @@ ask_olist(int combat_mode, struct combat *off, struct combat *def,
 		    att_mode[combat_mode],
 		    prland(&land),
 		    prcom(1, off),
-		    land.lnd_army == ' ' ? '~' : land.lnd_army,
+		    land.lnd_army ? land.lnd_army : '~',
 		    land.lnd_effic);
 	    land_answer[(int)land.lnd_army] =
 		att_prompt(prompt, land.lnd_army);
@@ -2293,7 +2293,7 @@ ask_move_in(struct combat *off, struct emp_qelem *olist,
 		continue;
 	    sprintf(prompt, "Move in with %s (%c %d%%) [ynYNq?] ",
 		    prland(&llp->land),
-		    llp->land.lnd_army == ' ' ? '~' : llp->land.lnd_army,
+		    llp->land.lnd_army ? llp->land.lnd_army :  '~',
 		    llp->land.lnd_effic);
 	    *answerp = att_prompt(prompt, llp->land.lnd_army);
 	    if (player->aborted || att_get_combat(def, 0) < 0)

src/lib/subs/lndsub.c

@@ -765,7 +765,7 @@ lnd_list(struct emp_qelem *land_list)
 	pr("%4d ", lnd->lnd_uid);
 	pr("%-16.16s ", llp->lcp->l_name);
 	prxy("%4d,%-4d ", lnd->lnd_x, lnd->lnd_y, llp->land.lnd_own);
-	pr("%c", lnd->lnd_army);
+	pr("%1.1s", &lnd->lnd_army);
 	pr("%4d%%", lnd->lnd_effic);
 	pr("%4d", lnd->lnd_item[I_SHELL]);
 	pr("%4d", lnd->lnd_item[I_GUN]);

src/lib/subs/shpsub.c

@@ -333,7 +333,7 @@ shp_list(struct emp_qelem *ship_list)
 	pr("%4d ", shp->shp_uid);
 	pr("%-16.16s ", mlp->mcp->m_name);
 	prxy("%4d,%-4d ", shp->shp_x, shp->shp_y, mlp->ship.shp_own);
-	pr("%c", shp->shp_fleet);
+	pr("%1.1s", &shp->shp_fleet);
 	pr("%4d%%", shp->shp_effic);
 	pr("%4d", shp->shp_item[I_MILIT]);
 	pr("%4d", shp->shp_item[I_SHELL]);

src/lib/subs/snxtitem.c

@@ -45,6 +45,9 @@
  * can select on NS_ALL, NS_AREA, NS_DIST, and NS_LIST.
  * iterate thru the "condarg" string looking
  * for arguments to compile into the nstr.
+ * Using this function for anything but command arguments is usually
+ * incorrect, because it respects conditionals.  Use the snxtitem_FOO()
+ * instead.
  */
 int
 snxtitem(struct nstr_item *np, int type, char *str)
@@ -195,7 +198,7 @@ void
 snxtitem_group(struct nstr_item *np, int type, char group)
 {
     if (group == '~')
-	group = ' ';
+	group = 0;
     memset(np, 0, sizeof(*np));
     np->cur = -1;
     np->sel = NS_GROUP;

src/lib/subs/takeover.c

@@ -206,6 +206,7 @@ takeover_plane(struct plnstr *pp, natid newown)
     pp->pln_own = newown;
     makenotlost(EF_PLANE, pp->pln_own, pp->pln_uid, pp->pln_x, pp->pln_y);
     pp->pln_mission = 0;
+    pp->pln_wing = 0;
     putplane(pp->pln_uid, pp);
 }
 
@@ -224,7 +225,7 @@ takeover_ship(struct shpstr *sp, natid newown, int hostile)
     sp->shp_own = newown;
     makenotlost(EF_SHIP, sp->shp_own, sp->shp_uid, sp->shp_x, sp->shp_y);
     sp->shp_mission = 0;
-    sp->shp_fleet = ' ';
+    sp->shp_fleet = 0;
     sp->shp_rflags = 0;
     /* Keep track of when this was taken over */
     time(&sp->shp_access);
@@ -279,7 +280,7 @@ takeover_land(struct lndstr *landp, natid newown, int hostile)
 	putland(landp->lnd_uid, landp);
 	return;
     }
-    landp->lnd_army = ' ';
+    landp->lnd_army = 0;
     landp->lnd_mobil = 0;
     landp->lnd_harden = 0;
     /* Keep track of when this was taken over */