From 297047a6b929f1c7ced03a7ea2a9464094758ccc Mon Sep 17 00:00:00 2001
From: Karishma Chadha <kchadha@media.mit.edu>
Date: Tue, 23 Apr 2019 11:44:45 -0400
Subject: [PATCH] Fix serialization of blockInfo mutation property to XML

---
 src/engine/blocks.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/engine/blocks.js b/src/engine/blocks.js
index db0d5a5bc..165d5096c 100644
--- a/src/engine/blocks.js
+++ b/src/engine/blocks.js
@@ -1108,8 +1108,14 @@ class Blocks {
         let mutationString = `<${mutation.tagName}`;
         for (const prop in mutation) {
             if (prop === 'children' || prop === 'tagName') continue;
-            const mutationValue = (typeof mutation[prop] === 'string') ?
+            let mutationValue = (typeof mutation[prop] === 'string') ?
                 xmlEscape(mutation[prop]) : mutation[prop];
+
+            // Handle dynamic extension blocks
+            if (prop === 'blockInfo') {
+                mutationValue = xmlEscape(JSON.stringify(mutation[prop]));
+            }
+
             mutationString += ` ${prop}="${mutationValue}"`;
         }
         mutationString += '>';