From 5a8d583d1978d473bdefbd9fd0074ce84c74b110 Mon Sep 17 00:00:00 2001
From: Emma Krantz <emma.krantz@data61.csiro.au>
Date: Fri, 3 May 2019 16:58:56 +1000
Subject: [PATCH] Made comment on image blob loading error handling clearer.

---
 Source/Core/Resource.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Source/Core/Resource.js b/Source/Core/Resource.js
index b5648423aa31..ad53a48f2ee4 100644
--- a/Source/Core/Resource.js
+++ b/Source/Core/Resource.js
@@ -944,7 +944,8 @@ define([
                     window.URL.revokeObjectURL(generatedBlobResource.url);
                 }
 
-                // We attach additional information to the error here so that it can be handled by an ImageProvider.
+                // If the blob load succeeded but the image decode failed, provide access to the blob on the error object because it may provide useful insight.
+                // In particular, BingMapsImageryProvider uses this to detect the zero-length "image" that some map styles return when a real tile is not available.
                 error.blob = generatedBlob;
 
                 return when.reject(error);