From bdc451d66beb6944dc4fbbfa19aef14fef457858 Mon Sep 17 00:00:00 2001
From: Justin Sleep <justin@midnightmechanism.com>
Date: Wed, 3 Jun 2020 16:36:48 -0500
Subject: [PATCH] Remove escape backslashes in non-Markdown messages

---
 src/Markdown.js               |  8 --------
 src/editor/serialize.ts       |  4 ++++
 test/editor/serialize-test.js | 12 ++++++++++++
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/Markdown.js b/src/Markdown.js
index fb1f8bf0ea..d312b7c5bd 100644
--- a/src/Markdown.js
+++ b/src/Markdown.js
@@ -175,14 +175,6 @@ export default class Markdown {
         const renderer = new commonmark.HtmlRenderer({safe: false});
         const real_paragraph = renderer.paragraph;
 
-        // The default `out` function only sends the input through an XML
-        // escaping function, which causes messages to be entity encoded,
-        // which we don't want in this case.
-        renderer.out = function(s) {
-            // The `lit` function adds a string literal to the output buffer.
-            this.lit(s);
-        };
-
         renderer.paragraph = function(node, entering) {
             // as with toHTML, only append lines to paragraphs if there are
             // multiple paragraphs
diff --git a/src/editor/serialize.ts b/src/editor/serialize.ts
index 4d0b8cd03a..85d2bb8e8f 100644
--- a/src/editor/serialize.ts
+++ b/src/editor/serialize.ts
@@ -42,6 +42,10 @@ export function htmlSerializeIfNeeded(model: EditorModel, {forceHTML = false} =
     if (!parser.isPlainText() || forceHTML) {
         return parser.toHTML();
     }
+    // ensure removal of escape backslashes in non-Markdown messages
+    if (md.indexOf("\\") > -1) {
+        return parser.toPlaintext();
+    }
 }
 
 export function textSerialize(model: EditorModel) {
diff --git a/test/editor/serialize-test.js b/test/editor/serialize-test.js
index bd26ae91bb..f0d577ea21 100644
--- a/test/editor/serialize-test.js
+++ b/test/editor/serialize-test.js
@@ -61,4 +61,16 @@ describe('editor/serialize', function() {
         const html = htmlSerializeIfNeeded(model, {});
         expect(html).toBe("<a href=\"https://matrix.to/#/@user:server\">Displayname]</a>");
     });
+    it('escaped markdown should not retain backslashes', function() {
+        const pc = createPartCreator();
+        const model = new EditorModel([pc.plain('\\*hello\\* world')]);
+        const html = htmlSerializeIfNeeded(model, {});
+        expect(html).toBe('*hello* world');
+    });
+    it('escaped markdown should convert HTML entities', function() {
+        const pc = createPartCreator();
+        const model = new EditorModel([pc.plain('\\*hello\\* world < hey world!')]);
+        const html = htmlSerializeIfNeeded(model, {});
+        expect(html).toBe('*hello* world &lt; hey world!');
+    });
 });