Added a way for love's reference-counted objects to be released more safely in some situations (e.g. setters)

src/common/Object.h

@@ -65,6 +65,33 @@ public:
 	 **/
 	virtual void release();
 
+	/**
+	 * Meant to be used as a temporary object. Facilitates safer and cleaner
+	 * code to release objects by doing so when the AutoRelease object is
+	 * destroyed (e.g. goes out of scope.)
+	 **/
+	class AutoRelease
+	{
+	public:
+
+		AutoRelease(Object *obj)
+			: object(obj)
+		{
+		}
+
+		~AutoRelease()
+		{
+			if (object)
+				object->release();
+		}
+
+	private:
+
+		AutoRelease() {}
+		Object *object;
+
+	}; // AutoRelease
+
 private:
 
 	// The reference count.

src/modules/graphics/opengl/Graphics.cpp

@@ -543,8 +543,7 @@ Color Graphics::getBackgroundColor() const
 
 void Graphics::setFont(Font *font)
 {
-	if (currentFont != 0)
-		currentFont->release();
+	Object::AutoRelease fontrelease(currentFont);
 
 	currentFont = font;
 

src/modules/graphics/opengl/ParticleSystem.cpp

@@ -193,8 +193,7 @@ void ParticleSystem::remove(particle *p)
 
 void ParticleSystem::setImage(Image *image)
 {
-	if (this->image != 0)
-		this->image->release();
+	Object::AutoRelease imagerelease(this->image);
 
 	this->image = image;
 	this->image->retain();

src/modules/graphics/opengl/SpriteBatch.cpp

@@ -176,8 +176,9 @@ void SpriteBatch::unlock()
 
 void SpriteBatch::setImage(Image *newimage)
 {
+	Object::AutoRelease imagerelease(image);
+
 	newimage->retain();
-	image->release();
 	image = newimage;
 }