From 530afb1a60461bdc6f9ab896a0137c25de256382 Mon Sep 17 00:00:00 2001
From: jmoenig <jens@moenig.org>
Date: Tue, 9 Apr 2019 10:27:55 +0200
Subject: [PATCH] let "getImageAttribute" deal with null costumes

---
 HISTORY.md     |  1 +
 src/objects.js | 21 +++++++++++++--------
 src/threads.js |  2 +-
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/HISTORY.md b/HISTORY.md
index d57bdc56..f0fd6a53 100755
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -64,6 +64,7 @@
 
 ### 2019-04-09
 * Blocks, Objects, Threads: new "getImageAttribute" reporter primitive
+* Objects, Threads: let "getImageAttribute" deal with null costumes 
 
 ### 2019-04-08
 * Blocks, Objects, Threads: new "getSoundAttribute" reporter primitive
diff --git a/src/objects.js b/src/objects.js
index 3c535eeb..43bab5d0 100644
--- a/src/objects.js
+++ b/src/objects.js
@@ -8910,14 +8910,19 @@ Costume.prototype.rasterized = function () {
 };
 
 Costume.prototype.pixels = function () {
-    var i,
-        pixels = [],
-        src = this.contents.getContext('2d').getImageData(
-            0,
-            0,
-            this.contents.width,
-            this.contents.height
-        );
+    var pixels = [],
+        src,
+        i;
+
+    if (!this.contents.width || !this.contents.height) {
+        return pixels;
+    }
+    src = this.contents.getContext('2d').getImageData(
+        0,
+        0,
+        this.contents.width,
+        this.contents.height
+    );
     for (i = 0; i < src.data.length; i += 4) {
         pixels.push(new List([
             src.data[i],
diff --git a/src/threads.js b/src/threads.js
index ff8a0686..1b6b7da5 100644
--- a/src/threads.js
+++ b/src/threads.js
@@ -4345,7 +4345,7 @@ Process.prototype.reportGetImageAttribute = function (choice, name) {
                     this.blockReceiver().costumes.asArray(),
                     function (c) {return c.name === name.toString(); }
                 )
-            ),
+            ) || new Costume(),
         option = this.inputOption(choice);
 
     switch (option) {