From c01b102f54770c37a62870f60a849b479aa3285c Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 25 Apr 2018 13:51:53 +0300
Subject: [PATCH] Throw key_error if an inherited Technique uses nonexistent
 texture slot

---
 source/technique.cpp | 16 +++++++++++-----
 source/technique.h   |  2 +-
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/source/technique.cpp b/source/technique.cpp
index 2b02f35f..def0a84a 100644
--- a/source/technique.cpp
+++ b/source/technique.cpp
@@ -28,15 +28,20 @@ const RenderPass &Technique::get_pass(const Tag &tag) const
 	return get_item(passes, tag);
 }
 
-void Technique::replace_texture(const string &slot, const Texture &tex)
+bool Technique::replace_texture(const string &slot, const Texture &tex)
 {
+	bool replaced = false;
 	for(PassMap::iterator i=passes.begin(); i!=passes.end(); ++i)
 	{
 		int index = i->second.get_texture_index(slot);
-		if(index<0)
-			continue;
-		i->second.set_texture(index, &tex);
+		if(index>=0)
+		{
+			i->second.set_texture(index, &tex);
+			replaced = true;
+		}
 	}
+
+	return replaced;
 }
 
 bool Technique::has_shaders() const
@@ -108,7 +113,8 @@ void Technique::InheritLoader::material(const string &pass_tag, const string &na
 
 void Technique::InheritLoader::texture(const string &slot, const string &name)
 {
-	obj.replace_texture(slot, get_collection().get<Texture>(name));
+	if(!obj.replace_texture(slot, get_collection().get<Texture>(name)))
+		throw key_error(slot);
 }
 
 } // namespace GL
diff --git a/source/technique.h b/source/technique.h
index 7ea69537..bed1db33 100644
--- a/source/technique.h
+++ b/source/technique.h
@@ -50,7 +50,7 @@ public:
 	bool has_pass(const Tag &) const;
 	const RenderPass &get_pass(const Tag &) const;
 	const PassMap &get_passes() const { return passes; }
-	void replace_texture(const std::string &, const Texture &);
+	bool replace_texture(const std::string &, const Texture &);
 	bool has_shaders() const;
 };
 
-- 
2.43.0