From d73ac0ff159ac68edf6d2ba1d674774b06f2516b Mon Sep 17 00:00:00 2001
From: Ansis Brammanis <brammanis@gmail.com>
Date: Thu, 4 Feb 2016 18:36:40 -0800
Subject: [PATCH] fix #2034, fix tile debug rendering

---
 js/render/draw_debug.js | 8 ++++----
 js/render/painter.js    | 4 +++-
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/js/render/draw_debug.js b/js/render/draw_debug.js
index 9544a8fe405..a86ad9c3b9e 100644
--- a/js/render/draw_debug.js
+++ b/js/render/draw_debug.js
@@ -5,20 +5,20 @@ var browser = require('../util/browser');
 
 module.exports = drawDebug;
 
-function drawDebug(painter, coords) {
+function drawDebug(painter, source, coords) {
     if (painter.isOpaquePass) return;
     if (!painter.options.debug) return;
 
     for (var i = 0; i < coords.length; i++) {
-        drawDebugTile(painter, coords[i]);
+        drawDebugTile(painter, source, coords[i]);
     }
 }
 
-function drawDebugTile(painter, coord) {
+function drawDebugTile(painter, source, coord) {
     var gl = painter.gl;
 
     var shader = painter.debugShader;
-    gl.switchShader(shader, painter.calculatePosMatrix(coord));
+    gl.switchShader(shader, painter.calculatePosMatrix(coord, source.maxzoom));
 
     // draw bounding rectangle
     gl.bindBuffer(gl.ARRAY_BUFFER, painter.debugBuffer);
diff --git a/js/render/painter.js b/js/render/painter.js
index 30059eb9964..fd2a8c4fa84 100644
--- a/js/render/painter.js
+++ b/js/render/painter.js
@@ -299,7 +299,9 @@ Painter.prototype.renderPass = function(options) {
             this.renderLayer(this, source, layer, coords);
         }
 
-        draw.debug(this, coords);
+        if (source) {
+            draw.debug(this, source, coords);
+        }
     }
 };