- make sure that incomplete multipatch textures are technically complete.

They need a valid FTexture backing them and should have their name cleared so that nothing references them by accident.

src/common/textures/multipatchtexturebuilder.cpp

@@ -923,7 +923,10 @@ void FMultipatchTextureBuilder::ResolveAllPatches()
 			for (auto &b : BuiltTextures)
 			{
 				Printf("%s\n", b.Name.GetChars());
+				// make it hard to find but also ensure that it references valid backing data.
 				b.texture->SetUseType(ETextureType::Null);
+				b.texture->SetBase(TexMan.GameByIndex(0)->GetTexture());
+				b.texture->SetName("");
 			}
 			break;
 		}

src/rendering/hwrenderer/hw_precache.cpp

@@ -104,7 +104,7 @@ void hw_PrecacheTexture(uint8_t *texhitlist, TMap<PClassActor*, bool> &actorhitl
 	for (int i = 1; i < TexMan.NumTextures(); i++)
 	{
 		auto gametex = TexMan.GameByIndex(i);
-		if (gametex &&
+		if (gametex && gametex->isValid() &&
 			gametex->GetTexture()->GetImage() &&	// only image textures are subject to precaching
 			gametex->GetUseType() != ETextureType::FontChar &&	// We do not want to delete font characters here as they are very likely to be needed constantly.
 			gametex->GetUseType() < ETextureType::Special)		// Any texture marked as 'special' is also out.