Merge default into minor

--HG--
branch : minor

src/modules/graphics/opengl/Canvas.cpp

@@ -501,13 +501,15 @@ void Canvas::startGrab()
 			gl.setFramebufferSRGB(false);
 	}
 
-	if (attachedCanvases.size() == 0)
-		return;
+	if (attachedCanvases.size() > 0)
+	{
+		// Make sure the FBO is only using a single draw buffer.
+		// GLES3 only has glDrawBuffers, so we avoid using glDrawBuffer.
+		const GLenum buffers[] = {GL_COLOR_ATTACHMENT0};
+		glDrawBuffers(1, buffers);
 
-	// Make sure the FBO is only using a single draw buffer.
-	glDrawBuffer(GL_COLOR_ATTACHMENT0);
-
-	attachedCanvases.clear();
+		attachedCanvases.clear();
+	}
 }
 
 void Canvas::stopGrab(bool switchingToOtherCanvas)

src/modules/graphics/opengl/wrap_Graphics.lua

@@ -352,13 +352,17 @@ function love.graphics.newVideo(file, loadaudio)
 	local video = love.graphics._newVideo(file)
 	local source, success
 
-	if loadaudio ~= false then
+	if loadaudio ~= false and love.audio then
 		success, source = pcall(love.audio.newSource, video:getStream():getFilename(), "stream")
 	end
 	if success then
 		video:setSource(source)
 	elseif loadaudio == true then
-		error("Video had no audio track", 2)
+		if love.audio then
+			error("Video had no audio track", 2)
+		else
+			error("love.audio was not loaded", 2)
+		end
 	else
 		video:getStream():setSync()
 	end