diff --git a/src/nodebuild_utility.cpp b/src/nodebuild_utility.cpp
index f25d747db..02e280261 100644
--- a/src/nodebuild_utility.cpp
+++ b/src/nodebuild_utility.cpp
@@ -616,12 +616,16 @@ void FNodeBuilder::FLevel::FindMapBounds()
 	minx = maxx = Vertices[0].fX();
 	miny = maxy = Vertices[0].fY();
 
-	for (int i = 1; i < NumVertices; ++i)
+	for (int i = 1; i < NumLines; ++i)
 	{
-		if (Vertices[i].fX() < minx) minx = Vertices[i].fX();
-		else if (Vertices[i].fX() > maxx) maxx = Vertices[i].fX();
-		if (Vertices[i].fY() < miny) miny = Vertices[i].fY();
-		else if (Vertices[i].fY() > maxy) maxy = Vertices[i].fY();
+		for (int j = 0; j < 2; j++)
+		{
+			vertex_t *v = (j == 0 ? Lines[i].v1 : Lines[i].v2);
+			if (v->fX() < minx) minx = v->fX();
+			else if (v->fX() > maxx) maxx = v->fX();
+			if (v->fY() < miny) miny = v->fY();
+			else if (v->fY() > maxy) maxy = v->fY();
+		}
 	}
 
 	MinX = FLOAT2FIXED(minx);
diff --git a/src/p_enemy.cpp b/src/p_enemy.cpp
index 227c1ab48..b7ad54095 100644
--- a/src/p_enemy.cpp
+++ b/src/p_enemy.cpp
@@ -255,6 +255,7 @@ void P_NoiseAlert (AActor *target, AActor *emitter, bool splash, double maxdist)
 		return;
 
 	validcount++;
+	NoiseList.Clear();
 	NoiseMarkSector(emitter->Sector, target, splash, emitter, 0, maxdist);
 	for (unsigned i = 0; i < NoiseList.Size(); i++)
 	{
diff --git a/src/portal.cpp b/src/portal.cpp
index 74d97b6e7..41f2e755e 100644
--- a/src/portal.cpp
+++ b/src/portal.cpp
@@ -1111,7 +1111,7 @@ void P_CreateLinkedPortals()
 	}
 
 	// reject would just get in the way when checking sight through portals.
-	if (rejectmatrix != NULL)
+	if (Displacements.size > 1 && rejectmatrix != NULL)
 	{
 		delete[] rejectmatrix;
 		rejectmatrix = NULL;
diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index feec1aceb..86de07b5d 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -1463,7 +1463,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_CustomBulletAttack)
 	PARAM_ANGLE		(spread_z);
 	PARAM_INT		(numbullets);
 	PARAM_INT		(damageperbullet);
-	PARAM_CLASS_OPT	(pufftype, AActor) { pufftype = PClass::FindActor(NAME_BulletPuff); }
+	PARAM_CLASS_OPT	(pufftype, AActor) { pufftype = nullptr; }
 	PARAM_FLOAT_OPT	(range)			   { range = 0; }
 	PARAM_INT_OPT	(flags)			   { flags = 0; }
 	PARAM_INT_OPT	(ptr)			   { ptr = AAPTR_TARGET; }
@@ -1487,6 +1487,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_CustomBulletAttack)
 		bangle = self->Angles.Yaw;
 
 		if (!(flags & CBAF_NOPITCH)) bslope = P_AimLineAttack (self, bangle, MISSILERANGE);
+		if (pufftype == nullptr) pufftype = PClass::FindActor(NAME_BulletPuff);
 
 		S_Sound (self, CHAN_WEAPON, self->AttackSound, 1, ATTN_NORM);
 		for (i = 0; i < numbullets; i++)