From 9c27a771b3dfa794ca37d45b4e4e75df34d8437d Mon Sep 17 00:00:00 2001
From: Markus Armbruster <armbru@pond.sub.org>
Date: Wed, 5 Apr 2006 09:13:03 +0000
Subject: [PATCH] (BestAirPath): Some callers assumed non-null return value
 must be the first argument.  Fix them.  Simplify bestownedpath().

---
 src/lib/common/bestpath.c | 16 ++++------------
 src/lib/subs/mission.c    | 17 +++++++++++------
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/src/lib/common/bestpath.c b/src/lib/common/bestpath.c
index 2356a1bb..be159102 100644
--- a/src/lib/common/bestpath.c
+++ b/src/lib/common/bestpath.c
@@ -145,7 +145,6 @@ bestownedpath(s_char *bpath,
     if (!mapindex)
 	return NULL;
 
-    bpath[0] = 0;
     if (0 != (restr2 = (*terrain == 'R')))
 	terrain++;
 
@@ -154,11 +153,8 @@ bestownedpath(s_char *bpath,
     ex = XNORM(ex);
     ey = YNORM(ey);
 
-    if (x == ex && y == ey) {
-	bpath[0] = 'h';
-	bpath[1] = 0;
-	return bpath;
-    }
+    if (x == ex && y == ey)
+	return "h";
 
     if (!valid(x, y) || !valid(ex, ey))
 	return NULL;
@@ -180,11 +176,8 @@ bestownedpath(s_char *bpath,
     maxy = y + 1;
 
     do {
-	if (++routelen == MAXROUTE) {
-	    bpath[0] = '?';
-	    bpath[1] = 0;
-	    return bpath;
-	}
+	if (++routelen == MAXROUTE)
+	    return "?";
 	markedsectors = 0;
 	for (scanx = minx; scanx <= maxx; scanx++) {
 	    x = XNORM(scanx);
@@ -229,7 +222,6 @@ bestownedpath(s_char *bpath,
 	maxx += 2;
     } while (markedsectors);
 
-    bpath[0] = 0;
     return NULL;		/* no route possible    */
 }
 
diff --git a/src/lib/subs/mission.c b/src/lib/subs/mission.c
index 8c71d9fd..51835d41 100644
--- a/src/lib/subs/mission.c
+++ b/src/lib/subs/mission.c
@@ -712,7 +712,8 @@ perform_mission(coord x, coord y, natid victim, struct emp_qelem *list,
 
     for (qp = airp.q_forw; qp != (&airp); qp = qp->q_forw) {
 	struct airport *air;
-	s_char pp[512];
+	char buf[512];
+	char *pp;
 
 	air = (struct airport *)qp;
 	md = mapdist(x, y, air->x, air->y);
@@ -734,14 +735,15 @@ perform_mission(coord x, coord y, natid victim, struct emp_qelem *list,
 	mission_flags = mission_pln_arm(&b, air->x, air->y, 2 * md, 'p', 0,
 					0, mission_flags, &tech);
 
-	if (QEMPTY(&b)) {
+	if (QEMPTY(&b))
 	    continue;
-	}
 
 	mission_flags = mission_pln_arm(&e, air->x, air->y, 2 * md, 'p', 0,
 					P_F | P_ESC, mission_flags, &tech);
 
-	BestAirPath(pp, air->x, air->y, x, y);
+	pp = BestAirPath(buf, air->x, air->y, x, y);
+	if (CANT_HAPPEN(!pp))
+	    continue;
 	wu(0, plane_owner, "Flying %s mission from %s\n",
 	   mission_name(mission), xyas(air->x, air->y, plane_owner));
 	if (air->own && (air->own != plane_owner)) {
@@ -1484,7 +1486,8 @@ air_defense(coord x, coord y, natid victim, struct emp_qelem *bomb_list,
     struct genlist *glp;
     struct genitem *gp;
     struct genlist mi[MAXNOC];
-    s_char path[512];
+    char buf[512];
+    char *path;
     int count;
     int tcount;
 
@@ -1618,7 +1621,9 @@ air_defense(coord x, coord y, natid victim, struct emp_qelem *bomb_list,
 		continue;
 	    }
 
-	    BestAirPath(path, air->x, air->y, x, y);
+	    path = BestAirPath(buf, air->x, air->y, x, y);
+	    if (CANT_HAPPEN(!path))
+		continue;
 	    wu(0, cn, "Flying %s mission from %s\n",
 	       mission_name(MI_AIR_DEFENSE), xyas(air->x, air->y, cn));
 	    if (air->own && (air->own != cn)) {