diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index ac1362295..733aef90d 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,8 @@
 December 25, 2009  (Changes by Graf Zahl)
+- Fixed: Decals could spread to walls which had a decal-less texture or
+  were flagged not to have decals.
+- Fixed: DBaseDecal/DImpactDecal::CloneSelf never checked the return value
+  from their StickToWall call and left unplaced decals behind if that happened.
 - Reintroduced Doom.exe's player_t::usedown variable so that respawning a
   player does not immediately activate switches. oldbuttons was not usable
   for this. This also required that CopyPlayer preserves this info.
diff --git a/src/g_shared/a_decals.cpp b/src/g_shared/a_decals.cpp
index 51a30e081..d992bec9e 100644
--- a/src/g_shared/a_decals.cpp
+++ b/src/g_shared/a_decals.cpp
@@ -298,6 +298,13 @@ FTextureID DBaseDecal::StickToWall (side_t *wall, fixed_t x, fixed_t y, F3DFloor
 	else return FNullTextureID();
 	CalcFracPos (wall, x, y);
 
+	FTexture *texture = TexMan[tex];
+
+	if (texture == NULL || texture->bNoDecals)
+	{
+		return FNullTextureID();
+	}
+
 	return tex;
 }
 
@@ -546,11 +553,18 @@ DBaseDecal *DBaseDecal::CloneSelf (const FDecalTemplate *tpl, fixed_t ix, fixed_
 	DBaseDecal *decal = new DBaseDecal(iz);
 	if (decal != NULL)
 	{
-		decal->StickToWall (wall, ix, iy, ffloor);
-		tpl->ApplyToDecal (decal, wall);
-		decal->AlphaColor = AlphaColor;
-		decal->RenderFlags = (decal->RenderFlags & RF_DECALMASK) |
-							 (this->RenderFlags & ~RF_DECALMASK);
+		if (decal->StickToWall (wall, ix, iy, ffloor).isValid())
+		{
+			tpl->ApplyToDecal (decal, wall);
+			decal->AlphaColor = AlphaColor;
+			decal->RenderFlags = (decal->RenderFlags & RF_DECALMASK) |
+								 (this->RenderFlags & ~RF_DECALMASK);
+		}
+		else
+		{
+			decal->Destroy();
+			return NULL;
+		}
 	}
 	return decal;
 }
@@ -652,16 +666,12 @@ DImpactDecal *DImpactDecal::StaticCreate (const FDecalTemplate *tpl, fixed_t x,
 		}
 		DImpactDecal::CheckMax();
 		decal = new DImpactDecal (z);
-
-		FTextureID stickypic = decal->StickToWall (wall, x, y, ffloor);
-		FTexture *tex = TexMan[stickypic];
-
-		if (tex != NULL && tex->bNoDecals)
+		if (decal == NULL)
 		{
 			return NULL;
 		}
 
-		if (decal == NULL)
+		if (!decal->StickToWall (wall, x, y, ffloor).isValid())
 		{
 			return NULL;
 		}
@@ -685,15 +695,27 @@ DImpactDecal *DImpactDecal::StaticCreate (const FDecalTemplate *tpl, fixed_t x,
 
 DBaseDecal *DImpactDecal::CloneSelf (const FDecalTemplate *tpl, fixed_t ix, fixed_t iy, fixed_t iz, side_t *wall, F3DFloor * ffloor) const
 {
+	if (wall->Flags & WALLF_NOAUTODECALS)
+	{
+		return NULL;
+	}
+
 	DImpactDecal::CheckMax();
 	DImpactDecal *decal = new DImpactDecal(iz);
 	if (decal != NULL)
 	{
-		decal->StickToWall (wall, ix, iy, ffloor);
-		tpl->ApplyToDecal (decal, wall);
-		decal->AlphaColor = AlphaColor;
-		decal->RenderFlags = (decal->RenderFlags & RF_DECALMASK) |
-							 (this->RenderFlags & ~RF_DECALMASK);
+		if (decal->StickToWall (wall, ix, iy, ffloor).isValid())
+		{
+			tpl->ApplyToDecal (decal, wall);
+			decal->AlphaColor = AlphaColor;
+			decal->RenderFlags = (decal->RenderFlags & RF_DECALMASK) |
+								 (this->RenderFlags & ~RF_DECALMASK);
+		}
+		else
+		{
+			decal->Destroy();
+			return NULL;
+		}
 	}
 	return decal;
 }