Deserialize back to math delimiters for editing

src/HtmlUtils.tsx

@@ -534,7 +534,6 @@ export function checkBlockNode(node: Node) {
         case "H6":
         case "PRE":
         case "BLOCKQUOTE":
-        case "DIV":
         case "P":
         case "UL":
         case "OL":
@@ -547,6 +546,9 @@ export function checkBlockNode(node: Node) {
         case "TH":
         case "TD":
             return true;
+        case "DIV":
+            // don't treat math nodes as block nodes for deserializing
+            return !(node as HTMLElement).hasAttribute("data-mx-maths");
         default:
             return false;
     }

src/editor/deserialize.ts

@@ -130,6 +130,18 @@ function parseElement(n: HTMLElement, partCreator: PartCreator, lastNode: HTMLEl
             }
             break;
         }
+        case "DIV":
+        case "SPAN": {
+            // math nodes are translated back into delimited latex strings
+            if (n.hasAttribute("data-mx-maths")) {
+                const delim = (n.nodeName == "SPAN") ? "$$" : "$$$";
+                const tex = n.getAttribute("data-mx-maths");
+                return partCreator.plain(delim + tex + delim);
+            } else if (!checkDescendInto(n)) {
+                return partCreator.plain(n.textContent);
+            }
+            break;
+        }
         case "OL":
             state.listIndex.push((<HTMLOListElement>n).start || 1);
             /* falls through */