From e561504d276ffb5f3713e0a864abdc1254d6c4a9 Mon Sep 17 00:00:00 2001
From: Andreas Hocevar <andreas.hocevar@gmail.com>
Date: Fri, 10 Feb 2017 10:05:07 +0000
Subject: [PATCH] Save and restore context when rotating

---
 src/ol/renderer/canvas/map.js | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/ol/renderer/canvas/map.js b/src/ol/renderer/canvas/map.js
index a0b484b7e7..f9801a630b 100644
--- a/src/ol/renderer/canvas/map.js
+++ b/src/ol/renderer/canvas/map.js
@@ -145,7 +145,10 @@ ol.renderer.canvas.Map.prototype.renderFrame = function(frameState) {
   var layerStatesArray = frameState.layerStatesArray;
   ol.array.stableSort(layerStatesArray, ol.renderer.Map.sortByZIndex);
 
-  ol.render.canvas.rotateAtOffset(context, rotation, width / 2, height / 2);
+  if (rotation) {
+    context.save();
+    ol.render.canvas.rotateAtOffset(context, rotation, width / 2, height / 2);
+  }
 
   var viewResolution = frameState.viewState.resolution;
   var i, ii, layer, layerRenderer, layerState;
@@ -162,7 +165,9 @@ ol.renderer.canvas.Map.prototype.renderFrame = function(frameState) {
     }
   }
 
-  ol.render.canvas.rotateAtOffset(context, -rotation, width / 2, height / 2);
+  if (rotation) {
+    context.restore();
+  }
 
   this.dispatchComposeEvent_(
       ol.render.EventType.POSTCOMPOSE, frameState);