From 9ff893f3e73eadfcfd64db080ff486b8a55c9a81 Mon Sep 17 00:00:00 2001
From: John Factotum <50942278+johnfactotum@users.noreply.github.com>
Date: Sat, 27 Jul 2024 09:17:33 +0800
Subject: [PATCH] Treat XHTML without xmlns as HTML

The XHTML 1.1 spec says

    The start tag of the root element of the document MUST explicitly
    contain an xmlns declaration for the XHTML namespace

There doesn't seem to be such a requirement in the WHATWG spec. But at
any rate browsers won't render it properly without the XHTML namespace.
---
 epub.js | 5 +++--
 mobi.js | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/epub.js b/epub.js
index 6993488..d955753 100644
--- a/epub.js
+++ b/epub.js
@@ -673,8 +673,9 @@ class Loader {
         if ([MIME.XHTML, MIME.HTML, MIME.SVG].includes(mediaType)) {
             let doc = new DOMParser().parseFromString(str, mediaType)
             // change to HTML if it's not valid XHTML
-            if (mediaType === MIME.XHTML && doc.querySelector('parsererror')) {
-                console.warn(doc.querySelector('parsererror').innerText)
+            if (mediaType === MIME.XHTML && (doc.querySelector('parsererror')
+            || !doc.documentElement?.namespaceURI)) {
+                console.warn(doc.querySelector('parsererror')?.innerText ?? 'Invalid XHTML')
                 item.mediaType = MIME.HTML
                 doc = new DOMParser().parseFromString(str, item.mediaType)
             }
diff --git a/mobi.js b/mobi.js
index 31ff1dc..116477d 100644
--- a/mobi.js
+++ b/mobi.js
@@ -1154,7 +1154,7 @@ class KF8 {
 
         // by default, type is XHTML; change to HTML if it's not valid XHTML
         let doc = this.parser.parseFromString(replaced, this.#type)
-        if (doc.querySelector('parsererror')) {
+        if (doc.querySelector('parsererror') || !doc.documentElement?.namespaceURI) {
             this.#type = MIME.HTML
             doc = this.parser.parseFromString(replaced, this.#type)
         }