From a160bdf4df5d2f870778e5ac22a623274f74c9f5 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Sun, 13 Oct 2019 14:04:54 +0300
Subject: [PATCH] Persist code block language when editing

Signed-off-by: Tulir Asokan <tulir@maunium.net>
---
 src/editor/deserialize.js | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/editor/deserialize.js b/src/editor/deserialize.js
index d41e413dbc..abcfbf7dd7 100644
--- a/src/editor/deserialize.js
+++ b/src/editor/deserialize.js
@@ -58,7 +58,16 @@ function parseLink(a, partCreator) {
 
 function parseCodeBlock(n, partCreator) {
     const parts = [];
-    const preLines = ("```\n" + n.textContent + "```").split("\n");
+    let language = "";
+    if (n.firstChild && n.firstChild.nodeName === "CODE") {
+        for (const className of n.firstChild.classList) {
+            if (className.startsWith("language-")) {
+                language = className.substr("language-".length);
+                break;
+            }
+        }
+    }
+    const preLines = ("```" + language + "\n" + n.textContent + "```").split("\n");
     preLines.forEach((l, i) => {
         parts.push(partCreator.plain(l));
         if (i < preLines.length - 1) {