- If A_SeekerMissile is used with the SMF_LOOK flag and its targets is unseekable, it now clears

its tracer so that it will look for a new target the next time it is called.
- Extended P_RoughMonsterSearch() with a flag to indicate that it should only search for seekable
  targets.

SVN r3572 (trunk)

src/g_hexen/a_clericholy.cpp

@@ -335,7 +335,7 @@ static void CHolyFindTarget (AActor *actor)
 {
 	AActor *target;
 
-	if ( (target = P_RoughMonsterSearch (actor, 6)) )
+	if ( (target = P_RoughMonsterSearch (actor, 6, true)) )
 	{
 		actor->tracer = target;
 		actor->flags |= MF_NOCLIP|MF_SKULLFLY;

src/g_hexen/a_magestaff.cpp

@@ -167,7 +167,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_MStaffTrack)
 {
 	if ((self->tracer == 0) && (pr_mstafftrack()<50))
 	{
-		self->tracer = P_RoughMonsterSearch (self, 10);
+		self->tracer = P_RoughMonsterSearch (self, 10, true);
 	}
 	P_SeekerMissile (self, ANGLE_1*2, ANGLE_1*10);
 }

src/p_local.h

@@ -350,7 +350,7 @@ public:
 #define PT_DELTA		8		// x2,y2 is passed as a delta, not as an endpoint
 
 AActor *P_BlockmapSearch (AActor *mo, int distance, AActor *(*check)(AActor*, int, void *), void *params = NULL);
-AActor *P_RoughMonsterSearch (AActor *mo, int distance);
+AActor *P_RoughMonsterSearch (AActor *mo, int distance, bool onlyseekable=false);
 
 //
 // P_MAP

src/p_maputl.cpp

@@ -1401,9 +1401,9 @@ FPathTraverse::~FPathTraverse()
 //		distance is in MAPBLOCKUNITS
 //===========================================================================
 
-AActor *P_RoughMonsterSearch (AActor *mo, int distance)
+AActor *P_RoughMonsterSearch (AActor *mo, int distance, bool onlyseekable)
 {
-	return P_BlockmapSearch (mo, distance, RoughBlockCheck);
+	return P_BlockmapSearch (mo, distance, RoughBlockCheck, (void *)onlyseekable);
 }
 
 AActor *P_BlockmapSearch (AActor *mo, int distance, AActor *(*check)(AActor*, int, void *), void *params)
@@ -1501,14 +1501,19 @@ AActor *P_BlockmapSearch (AActor *mo, int distance, AActor *(*check)(AActor*, in
 //
 //===========================================================================
 
-static AActor *RoughBlockCheck (AActor *mo, int index, void *)
+static AActor *RoughBlockCheck (AActor *mo, int index, void *param)
 {
+	bool onlyseekable = param != NULL;
 	FBlockNode *link;
 
 	for (link = blocklinks[index]; link != NULL; link = link->NextActor)
 	{
 		if (link->Me != mo)
 		{
+			if (onlyseekable && !mo->CanSeek(link->Me))
+			{
+				continue;
+			}
 			if (mo->IsOkayToAttack (link->Me))
 			{
 				return link->Me;

src/thingdef/thingdef_codeptr.cpp

@@ -501,9 +501,15 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_SeekerMissile)
 
 	if ((flags & SMF_LOOK) && (self->tracer == 0) && (pr_seekermissile()<chance))
 	{
-		self->tracer = P_RoughMonsterSearch (self, distance);
+		self->tracer = P_RoughMonsterSearch (self, distance, true);
+	}
+	if (!P_SeekerMissile(self, clamp<int>(ang1, 0, 90) * ANGLE_1, clamp<int>(ang2, 0, 90) * ANGLE_1, !!(flags & SMF_PRECISE), !!(flags & SMF_CURSPEED)))
+	{
+		if (flags & SMF_LOOK)
+		{ // This monster is no longer seekable, so let us look for another one next time.
+			self->tracer = NULL;
+		}
 	}
-	P_SeekerMissile(self, clamp<int>(ang1, 0, 90) * ANGLE_1, clamp<int>(ang2, 0, 90) * ANGLE_1, !!(flags & SMF_PRECISE), !!(flags & SMF_CURSPEED));
 }
 
 //==========================================================================