Refactor: Show the block where an error occured in a custom block

src/blocks.js

@@ -4192,24 +4192,6 @@ BlockMorph.prototype.scriptPic = function () {
     return pic;
 };
 
-BlockMorph.prototype.errorPic = function () {
-    // return a picture of myself, that approximately fits in "one line"
-    // filter any blocks beneath me, so that users only see the first
-    // block that caused an error.
-    var block = this;
-    if (block.selector === 'reportGetVar') {
-        // if I am a single variable, show my caller in the output.
-        block = block.parent;
-    }
-    if (block.nextBlock) {
-        var copy = block.fullCopy();
-        copy.removeChild(copy.nextBlock());
-        return copy.fullImage();
-    }
-
-    return block.fullImage();
-}
-
 BlockMorph.prototype.fullImage = function () {
     // answer a canvas image meant for (semi-) transparent blocks
     // that lets the background shine through

src/threads.js

@@ -1181,18 +1181,16 @@ Process.prototype.errorBubble = function (error, element) {
             `${errorPrefix}${localize(error.name)}:\n${localize(error.message)}`,
             SyntaxElementMorph.prototype.fontSize
         ),
-        img, blockImage;
+        blockToShow = element;
 
     errorMorph.add(errorMessage);
-    errorMorph.alpha = 0;
     if (errorIsNested) {
+        if (blockToShow.selector === 'reportGetVar') {
+            // if I am a single variable, show my caller in the output.
+            blockToShow = blockToShow.parent;
+        }
         errorMorph.text += `\n${localize('The error occured at:')}\n`;
-        img = element.errorPic();
-        blockImage = new Morph();
-        blockImage.isCachingImage = true;
-        blockImage.setExtent(new Point(img.width, img.height));
-        blockImage.cachedImage = img;
-        errorMorph.add(blockImage);
+        errorMorph.add(blockToShow);
         errorMorph.fixLayout();
     }